22972721 has 4 divisors (see below), whose sum is σ = 22983744. Its totient is φ = 22961700.

The previous prime is 22972717. The next prime is 22972757. The reversal of 22972721 is 12727922.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 22972721 - 2² = 22972717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22972421) 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, 1325 + ... + 6906.

It is an arithmetic number, because the mean of its divisors is an integer number (5745936).

Almost surely, 2^22972721 is an apocalyptic number.

It is an amenable number.

22972721 is a deficient number, since it is larger than the sum of its proper divisors (11023).

22972721 is an equidigital number, since it uses as much as digits as its factorization.

22972721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11022.

The product of its digits is 7056, while the sum is 32.

The square root of 22972721 is about 4792.9866471752. The cubic root of 22972721 is about 284.2742218434.

The spelling of 22972721 in words is "twenty-two million, nine hundred seventy-two thousand, seven hundred twenty-one".