23131581 has 16 divisors (see below), whose sum is σ = 33965568. Its totient is φ = 13886000.

The previous prime is 23131573. The next prime is 23131601. The reversal of 23131581 is 18513132.

It is a cyclic number.

It is not a de Polignac number, because 23131581 - 2³ = 23131573 is a prime.

It is a super-2 number, since 2×23131581² = 1070140079119122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23131081) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 256 + ... + 6806.

It is an arithmetic number, because the mean of its divisors is an integer number (2122848).

Almost surely, 2^23131581 is an apocalyptic number.

It is an amenable number.

23131581 is a deficient number, since it is larger than the sum of its proper divisors (10833987).

23131581 is a wasteful number, since it uses less digits than its factorization.

23131581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6672.

The product of its digits is 720, while the sum is 24.

The square root of 23131581 is about 4809.5302265398. The cubic root of 23131581 is about 284.9279842664.

The spelling of 23131581 in words is "twenty-three million, one hundred thirty-one thousand, five hundred eighty-one".