22731 has 4 divisors (see below), whose sum is σ = 30312. Its totient is φ = 15152.

The previous prime is 22727. The next prime is 22739. The reversal of 22731 is 13722.

22731 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 22731 - 2² = 22727 is a prime.

It is a super-2 number, since 2×22731² = 1033396722, which contains 22 as substring.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 22731.

It is not an unprimeable number, because it can be changed into a prime (22739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3786 + ... + 3791.

It is an arithmetic number, because the mean of its divisors is an integer number (7578).

2²²⁷³¹ is an apocalyptic number.

22731 is a deficient number, since it is larger than the sum of its proper divisors (7581).

22731 is an equidigital number, since it uses as much as digits as its factorization.

22731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7580.

The product of its digits is 84, while the sum is 15.

The square root of 22731 is about 150.7680337472. The cubic root of 22731 is about 28.3273651405.

Subtracting from 22731 its reverse (13722), we obtain a palindrome (9009).

The spelling of 22731 in words is "twenty-two thousand, seven hundred thirty-one".