23157731 has 4 divisors (see below), whose sum is σ = 23199000. Its totient is φ = 23116464.

The previous prime is 23157727. The next prime is 23157749. The reversal of 23157731 is 13775132.

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 23157731 - 2² = 23157727 is a prime.

It is a super-2 number, since 2×23157731² = 1072561010136722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 23157694 and 23157703.

It is not an unprimeable number, because it can be changed into a prime (23157721) 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, 19781 + ... + 20918.

It is an arithmetic number, because the mean of its divisors is an integer number (5799750).

Almost surely, 2^23157731 is an apocalyptic number.

23157731 is a deficient number, since it is larger than the sum of its proper divisors (41269).

23157731 is an equidigital number, since it uses as much as digits as its factorization.

23157731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41268.

The product of its digits is 4410, while the sum is 29.

The square root of 23157731 is about 4812.2480193772. The cubic root of 23157731 is about 285.0353131579.

The spelling of 23157731 in words is "twenty-three million, one hundred fifty-seven thousand, seven hundred thirty-one".