51690 has 16 divisors (see below), whose sum is σ = 124128. Its totient is φ = 13776.

The previous prime is 51683. The next prime is 51691. The reversal of 51690 is 9615.

It is a super-2 number, since 2×51690² = 5343712200, which contains 22 as substring.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (51691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 832 + ... + 891.

It is an arithmetic number, because the mean of its divisors is an integer number (7758).

2⁵¹⁶⁹⁰ is an apocalyptic number.

51690 is an abundant number, since it is smaller than the sum of its proper divisors (72438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (62064).

51690 is a wasteful number, since it uses less digits than its factorization.

51690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1733.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 51690 is about 227.3543489797. The cubic root of 51690 is about 37.2507919895.

It can be divided in two parts, 516 and 90, that added together give a palindrome (606).

The spelling of 51690 in words is "fifty-one thousand, six hundred ninety".