23131605 has 16 divisors (see below), whose sum is σ = 42297984. Its totient is φ = 10574400.

The previous prime is 23131601. The next prime is 23131609. The reversal of 23131605 is 50613132.

It is an interprime number because it is at equal distance from previous prime (23131601) and next prime (23131609).

It is not a de Polignac number, because 23131605 - 2² = 23131601 is a prime.

It is a super-2 number, since 2×23131605² = 1070142299752050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23131601) 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, 110046 + ... + 110255.

It is an arithmetic number, because the mean of its divisors is an integer number (2643624).

Almost surely, 2^23131605 is an apocalyptic number.

It is an amenable number.

23131605 is a deficient number, since it is larger than the sum of its proper divisors (19166379).

23131605 is a wasteful number, since it uses less digits than its factorization.

23131605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220316.

The product of its (nonzero) digits is 540, while the sum is 21.

The square root of 23131605 is about 4809.5327215853. The cubic root of 23131605 is about 284.9280828080.

Adding to 23131605 its reverse (50613132), we get a palindrome (73744737).

The spelling of 23131605 in words is "twenty-three million, one hundred thirty-one thousand, six hundred five".