51831 has 12 divisors (see below), whose sum is σ = 80808. Its totient is φ = 31824.

The previous prime is 51829. The next prime is 51839. The reversal of 51831 is 13815.

It is a happy number.

It is not a de Polignac number, because 51831 - 2¹ = 51829 is a prime.

It is a super-2 number, since 2×51831² = 5372905122, which contains 22 as substring.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51839) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 105 + ... + 338.

It is an arithmetic number, because the mean of its divisors is an integer number (6734).

2⁵¹⁸³¹ is an apocalyptic number.

51831 is a deficient number, since it is larger than the sum of its proper divisors (28977).

51831 is a wasteful number, since it uses less digits than its factorization.

51831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462 (or 459 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 51831 is about 227.6642264389. The cubic root of 51831 is about 37.2846321462.

It can be divided in two parts, 5183 and 1, that added together give a square (5184 = 72²).

The spelling of 51831 in words is "fifty-one thousand, eight hundred thirty-one".