72122218731538 has 16 divisors (see below), whose sum is σ = 109177264710360. Its totient is φ = 35729805822336.

The previous prime is 72122218731529. The next prime is 72122218731557. The reversal of 72122218731538 is 83513781222127.

It can be written as a sum of positive squares in 4 ways, for example, as 69265554243649 + 2856664487889 = 8322593^2 + 1690167^2 .

It is a super-2 number, since 2×72122218731538² (a number of 29 digits) contains 22 as substring.

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, 14833470 + ... + 19086022.

Almost surely, 2^{72122218731538} is an apocalyptic number.

72122218731538 is a deficient number, since it is larger than the sum of its proper divisors (37055045978822).

72122218731538 is a wasteful number, since it uses less digits than its factorization.

72122218731538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4330461.

The product of its digits is 2257920, while the sum is 52.

The spelling of 72122218731538 in words is "seventy-two trillion, one hundred twenty-two billion, two hundred eighteen million, seven hundred thirty-one thousand, five hundred thirty-eight".