172122239521 has 12 divisors (see below), whose sum is σ = 173299238032. Its totient is φ = 170949240000.

The previous prime is 172122239519. The next prime is 172122239537. The reversal of 172122239521 is 125932221271.

It is not a de Polignac number, because 172122239521 - 2¹ = 172122239519 is a prime.

It is a Duffinian number.

172122239521 is a Rhonda number in base 10.

Its product of digits (30240) is a multiple of the sum of its prime factors (3024).

It is not an unprimeable number, because it can be changed into a prime (172122239561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163769446 + ... + 163770496.

Almost surely, 2^172122239521 is an apocalyptic number.

172122239521 is the 221761-st nonagonal number.

It is an amenable number.

172122239521 is a deficient number, since it is larger than the sum of its proper divisors (1176998511).

172122239521 is an frugal number, since it uses more digits than its factorization.

172122239521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3024 (or 2143 counting only the distinct ones).

The product of its digits is 30240, while the sum is 37.

The spelling of 172122239521 in words is "one hundred seventy-two billion, one hundred twenty-two million, two hundred thirty-nine thousand, five hundred twenty-one".