23156521 has 4 divisors (see below), whose sum is σ = 23218000. Its totient is φ = 23095044.

The previous prime is 23156503. The next prime is 23156591. The reversal of 23156521 is 12565132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 23156521 - 2¹³ = 23148329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23156501) 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, 30171 + ... + 30928.

It is an arithmetic number, because the mean of its divisors is an integer number (5804500).

Almost surely, 2^23156521 is an apocalyptic number.

It is an amenable number.

23156521 is a deficient number, since it is larger than the sum of its proper divisors (61479).

23156521 is an equidigital number, since it uses as much as digits as its factorization.

23156521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61478.

The product of its digits is 1800, while the sum is 25.

The square root of 23156521 is about 4812.1222968665. The cubic root of 23156521 is about 285.0303486713.

It can be divided in two parts, 2315 and 6521, that added together give a square (8836 = 94²).

The spelling of 23156521 in words is "twenty-three million, one hundred fifty-six thousand, five hundred twenty-one".