172991854872 has 40 divisors (see below), whose sum is σ = 484537373100. Its totient is φ = 57663951408.

The previous prime is 172991854859. The next prime is 172991854877. The reversal of 172991854872 is 278458199271.

172991854872 is a `hidden beast` number, since 1 + 7 + 2 + 9 + 9 + 18 + 548 + 72 = 666.

It is a super-2 number, since 2×172991854872² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (172991854877) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 133480722 + ... + 133482017.

Almost surely, 2^172991854872 is an apocalyptic number.

172991854872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

172991854872 is an abundant number, since it is smaller than the sum of its proper divisors (311545518228).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

172991854872 is a wasteful number, since it uses less digits than its factorization.

172991854872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266962757 (or 266962744 counting only the distinct ones).

The product of its digits is 20321280, while the sum is 63.

The spelling of 172991854872 in words is "one hundred seventy-two billion, nine hundred ninety-one million, eight hundred fifty-four thousand, eight hundred seventy-two".