22131231 has 4 divisors (see below), whose sum is σ = 29508312. Its totient is φ = 14754152.

The previous prime is 22131223. The next prime is 22131259. The reversal of 22131231 is 13213122.

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 22131231 - 2³ = 22131223 is a prime.

It is a super-2 number, since 2×22131231² = 979582771150722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 22131231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22131211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3688536 + ... + 3688541.

It is an arithmetic number, because the mean of its divisors is an integer number (7377078).

Almost surely, 2^22131231 is an apocalyptic number.

22131231 is a deficient number, since it is larger than the sum of its proper divisors (7377081).

22131231 is an equidigital number, since it uses as much as digits as its factorization.

22131231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7377080.

The product of its digits is 72, while the sum is 15.

The square root of 22131231 is about 4704.3842317566. The cubic root of 22131231 is about 280.7599719933.

Adding to 22131231 its reverse (13213122), we get a palindrome (35344353).

The spelling of 22131231 in words is "twenty-two million, one hundred thirty-one thousand, two hundred thirty-one".