72323570665721 has 4 divisors (see below), whose sum is σ = 72331607520000. Its totient is φ = 72315533811444.

The previous prime is 72323570665711. The next prime is 72323570665751. The reversal of 72323570665721 is 12756607532327.

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 72323570665721 - 2³⁴ = 72306390796537 is a prime.

It is a super-2 number, since 2×72323570665721² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72323570665711) 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, 4018413641 + ... + 4018431638.

It is an arithmetic number, because the mean of its divisors is an integer number (18082901880000).

Almost surely, 2^{72323570665721} is an apocalyptic number.

It is an amenable number.

72323570665721 is a deficient number, since it is larger than the sum of its proper divisors (8036854279).

72323570665721 is an equidigital number, since it uses as much as digits as its factorization.

72323570665721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8036854278.

The product of its (nonzero) digits is 22226400, while the sum is 56.

The spelling of 72323570665721 in words is "seventy-two trillion, three hundred twenty-three billion, five hundred seventy million, six hundred sixty-five thousand, seven hundred twenty-one".