One thing I do in my spare time is to help out with the twitter for our local cycling campaign. They are an enthusiastic group and I love being involved with something that is so current. As a keen cyclist (tandem) it’s of great interest to me to see improvements for bike routes, bike parking etc. around the city. I’m trying to make the tweets as interesting and as engaging as possible. To this end I’ve run a few polls. The most successful was when I asked people to give a rough estimate of how far they ride each week. As twitter polls only allow four categories I tried to judge where the average would be and use this as a starting point. I thought that the average would be at about 50 miles a week minimum – perhaps 10 miles a day for commute, some leisure at the weekend and maybe some errands. But, surprisingly, the average was far lower than this as you can see from the photograph.

Together Howard (my husband) and I cycle between 10 and 30 miles most weeks – usually just one trip out at the weekend. Howard also tries to go by bike every time he goes into the city – about a 10-mile round trip. So he’s probably in the third category and I’m in the second.

I wondered how these results would look if I’d run the poll in a more cycling-friendly city – say one in Holland. I expect that the middle two categories would contain far more votes as cycling is more of a way of life there.

I was really pleased that 139 people voted. The other two polls I’ve run have attracted far fewer votes. I thought that 139 would be a great number to choose for this blog post.

Now comes the fun, random travel part. I start by looking up flights with 139 in the number to see where they take me. I love this because often destinations come up which I’d never considered before and I find myself thinking of places to visit that I wouldn’t have done otherwise. The British Airways flight BA139 goes between London and Mumbai. So Mumbai is my destination for this post.


A typical road in Mumbai – c/o

What do I know about Mumbai? Well, almost nothing. I’ve never been to India and have always wanted to go so I was delighted that Mumbai had come up for this blog post. I always consider cycling and food first when looking at a new place to go as I am passionate about both.

Given the photograph above, I was not optimistic about cycling in Mumbai! One of the first things I read about cycling in Mumbai was:

“Is it safe to cycle in Mumbai?

Cycling in Mumbai is quite safe during early mornings and late nights. There are a lot of cityscape views that you could enjoy on a cycle.”

Thus, I think that a cycling tour would be the best bet. We have been on one before and it wasn’t a great success. One reason was that many of the cyclists weren’t keen to stop and take in the scenery and we felt stifled because we couldn’t stop when we chose to. We like to go at our own pace and design our own routes. If we did cycle in Mumbai we’d need to compromise on our independence.

I absolutely love Indian food and believe that I have had quite an authentic experience having lived near the Curry Mile in Manchester. I looked up food specific to Mumbai and everything in this article except the goat’s brain dish appeals. Howard would try everything and I’d try some of his Bombay Duck (fish) and anything else I was wary of.

Although food in Mumbai sounds amazing the fear of getting ill is a real one for me. I found this article full of sound advice and it genuinely put my concerns to rest. I think that if I didn’t battle through fear then I would genuinely be missing out.

As far as places to visit, I genuinely felt thrilled reading through this article and would love to visit all 15 suggestions. In fact, if I visited Mumbai I’d love to do a wider trip into India. Given this cursory look at Mumbai what is the likelihood that I’d go? India itself is definitely a 10 / 10 for me. Whether I would go to Mumbai specifically I don’t know. Reading these articles has given me more confidence about managing tummy upsets.

Deficient Numbers

Like some of the other numbers that I’ve mentioned in my posts, 139 is prime – that is its only divisors are 1 and itself. This means that many of the number properties that have been discussed in these posts don’t apply. One property that does apply is that all prime numbers are deficient which means that the sum of their proper divisors (i.e. those less than themselves) add up to a smaller number.  With prime numbers, each of them has only one proper divisor – i.e. 1 –so they are all deficient.

Not all deficient numbers are prime. For example, the first few deficient numbers are:

1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 19, 21, 22 and so on.

16 is not prime and its proper divisors are 1, 2, 4, 8.

1 + 2 + 4 + 8 = 15, less than 16 so 16 is deficient.

Now, 20 is an abundant number (that is, not deficient) – you can see that it’s not in the list above. If we go through the steps:

The proper divisors of 20 are 1, 2, 4, 5, 10

1 + 2 + 4 + 5 + 10 = 22 which is greater than 20.

To me, it is unreasonable to label prime numbers as deficient. Mathematicians love prime numbers and they have real-world uses too – such as protecting data via encryption techniques. I think that prime numbers have slipped through the net on this one.

Last Thoughts

Well, my cycling twitter poll has led me on a virtual journey to Mumbai and a frustrating time learning that all primes are deficient even though, in real-life, they aren’t. I really do hope to visit India one day and, after having written this, I’m more enthusiastic than ever!