22031231 has 4 divisors (see below), whose sum is σ = 22249464. Its totient is φ = 21813000.

The previous prime is 22031209. The next prime is 22031237. The reversal of 22031231 is 13213022.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22031231 is a prime.

It is a super-2 number, since 2×22031231² = 970750278750722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22031237) 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, 108965 + ... + 109166.

It is an arithmetic number, because the mean of its divisors is an integer number (5562366).

Almost surely, 2^22031231 is an apocalyptic number.

22031231 is a deficient number, since it is larger than the sum of its proper divisors (218233).

22031231 is a wasteful number, since it uses less digits than its factorization.

22031231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218232.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 22031231 is about 4693.7438149094. The cubic root of 22031231 is about 280.3364620250.

Adding to 22031231 its reverse (13213022), we get a palindrome (35244253).

The spelling of 22031231 in words is "twenty-two million, thirty-one thousand, two hundred thirty-one".