23155731 has 6 divisors (see below), whose sum is σ = 33447180. Its totient is φ = 15437148.

The previous prime is 23155723. The next prime is 23155757. The reversal of 23155731 is 13755132.

It is not a de Polignac number, because 23155731 - 2³ = 23155723 is a prime.

It is a super-2 number, since 2×23155731² = 1072375756288722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 23155695 and 23155704.

It is not an unprimeable number, because it can be changed into a prime (23155711) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1286421 + ... + 1286438.

It is an arithmetic number, because the mean of its divisors is an integer number (5574530).

Almost surely, 2^23155731 is an apocalyptic number.

23155731 is a deficient number, since it is larger than the sum of its proper divisors (10291449).

23155731 is a wasteful number, since it uses less digits than its factorization.

23155731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2572865 (or 2572862 counting only the distinct ones).

The product of its digits is 3150, while the sum is 27.

The square root of 23155731 is about 4812.0402118021. The cubic root of 23155731 is about 285.0271073016.

The spelling of 23155731 in words is "twenty-three million, one hundred fifty-five thousand, seven hundred thirty-one".