23987531 has 6 divisors (see below), whose sum is σ = 24511020. Its totient is φ = 23474996.

The previous prime is 23987503. The next prime is 23987533. The reversal of 23987531 is 13578932.

It is a de Polignac number, because none of the positive numbers 2^k-23987531 is a prime.

It is a super-2 number, since 2×23987531² = 1150803286951922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23987533) 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, 3221 + ... + 7638.

It is an arithmetic number, because the mean of its divisors is an integer number (4085170).

Almost surely, 2^23987531 is an apocalyptic number.

23987531 is a deficient number, since it is larger than the sum of its proper divisors (523489).

23987531 is an equidigital number, since it uses as much as digits as its factorization.

23987531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10953 (or 10906 counting only the distinct ones).

The product of its digits is 45360, while the sum is 38.

The square root of 23987531 is about 4897.7067082462. The cubic root of 23987531 is about 288.3999514916.

The spelling of 23987531 in words is "twenty-three million, nine hundred eighty-seven thousand, five hundred thirty-one".