25631 has 6 divisors (see below), whose sum is σ = 27432. Its totient is φ = 23940.

The previous prime is 25621. The next prime is 25633. The reversal of 25631 is 13652.

It is a de Polignac number, because none of the positive numbers 2^k-25631 is a prime.

It is a super-2 number, since 2×25631² = 1313896322, which contains 22 as substring.

It is a Duffinian number.

Its product of digits (180) is a multiple of the sum of its prime divisors (90).

It is a plaindrome in base 12.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25633) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 326 + ... + 396.

It is an arithmetic number, because the mean of its divisors is an integer number (4572).

2²⁵⁶³¹ is an apocalyptic number.

25631 is a deficient number, since it is larger than the sum of its proper divisors (1801).

25631 is an equidigital number, since it uses as much as digits as its factorization.

25631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109 (or 90 counting only the distinct ones).

The product of its digits is 180, while the sum is 17.

The square root of 25631 is about 160.0968456904. The cubic root of 25631 is about 29.4841435422.

It can be divided in two parts, 25 and 631, that added together give a palindrome (656).

The spelling of 25631 in words is "twenty-five thousand, six hundred thirty-one".