72220688521 has 4 divisors (see below), whose sum is σ = 72308017872. Its totient is φ = 72133359172.

The previous prime is 72220688513. The next prime is 72220688563. The reversal of 72220688521 is 12588602227.

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 72220688521 - 2³ = 72220688513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (72220668521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43663435 + ... + 43665088.

It is an arithmetic number, because the mean of its divisors is an integer number (18077004468).

Almost surely, 2^72220688521 is an apocalyptic number.

It is an amenable number.

72220688521 is a deficient number, since it is larger than the sum of its proper divisors (87329351).

72220688521 is an equidigital number, since it uses as much as digits as its factorization.

72220688521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87329350.

The product of its (nonzero) digits is 215040, while the sum is 43.

The spelling of 72220688521 in words is "seventy-two billion, two hundred twenty million, six hundred eighty-eight thousand, five hundred twenty-one".