172991125188 has 144 divisors (see below), whose sum is σ = 505966755840. Its totient is φ = 48814944192.

The previous prime is 172991125157. The next prime is 172991125199. The reversal of 172991125188 is 881521199271.

It is a happy number.

172991125188 is a `hidden beast` number, since 1 + 7 + 2 + 9 + 9 + 112 + 518 + 8 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7124773 + ... + 7149011.

Almost surely, 2^172991125188 is an apocalyptic number.

172991125188 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 172991125188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252983377920).

172991125188 is an abundant number, since it is smaller than the sum of its proper divisors (332975630652).

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

172991125188 is a wasteful number, since it uses less digits than its factorization.

172991125188 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24606 (or 24601 counting only the distinct ones).

The product of its digits is 725760, while the sum is 54.

The spelling of 172991125188 in words is "one hundred seventy-two billion, nine hundred ninety-one million, one hundred twenty-five thousand, one hundred eighty-eight".