23563721 has 4 divisors (see below), whose sum is σ = 23650944. Its totient is φ = 23476500.

The previous prime is 23563703. The next prime is 23563723. The reversal of 23563721 is 12736532.

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 a de Polignac number, because none of the positive numbers 2^k-23563721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (23563723) 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, 43205 + ... + 43746.

It is an arithmetic number, because the mean of its divisors is an integer number (5912736).

Almost surely, 2^23563721 is an apocalyptic number.

It is an amenable number.

23563721 is a deficient number, since it is larger than the sum of its proper divisors (87223).

23563721 is an equidigital number, since it uses as much as digits as its factorization.

23563721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87222.

The product of its digits is 7560, while the sum is 29.

The square root of 23563721 is about 4854.2477275063. The cubic root of 23563721 is about 286.6913726378.

The spelling of 23563721 in words is "twenty-three million, five hundred sixty-three thousand, seven hundred twenty-one".