61

61 is a prime number.

The 61st Fibonacci number (2504730781961) is the smallest Fibonacci number that contains all the digits from 0 to 9.

61 is the smallest prime whose reversal (16) is a square.

There are 61 abstract groups of order 1464. Note that 61 divides 1464.

59 and 61 are twin primes.


The official length of an ice hockey rink must be no more than 61 meters.

Source: Number Gossip