72155621570 has 16 divisors (see below), whose sum is σ = 129883584888. Its totient is φ = 28861478400.

The previous prime is 72155621563. The next prime is 72155621581. The reversal of 72155621570 is 7512655127.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 71732373241 + 423248329 = 267829^2 + 20573^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 438770 + ... + 580370.

Almost surely, 2^72155621570 is an apocalyptic number.

72155621570 is a deficient number, since it is larger than the sum of its proper divisors (57727963318).

72155621570 is a wasteful number, since it uses less digits than its factorization.

72155621570 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192565.

The product of its (nonzero) digits is 147000, while the sum is 41.

The spelling of 72155621570 in words is "seventy-two billion, one hundred fifty-five million, six hundred twenty-one thousand, five hundred seventy".