172138779800 has 48 divisors (see below), whose sum is σ = 431009028240. Its totient is φ = 63558933120.

The previous prime is 172138779781. The next prime is 172138779803. The reversal of 172138779800 is 8977831271.

It is a super-2 number, since 2×172138779800² (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 (172138779803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 33101012 + ... + 33106211.

It is an arithmetic number, because the mean of its divisors is an integer number (8979354755).

Almost surely, 2^172138779800 is an apocalyptic number.

172138779800 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172138779800 is an abundant number, since it is smaller than the sum of its proper divisors (258870248440).

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

172138779800 is a wasteful number, since it uses less digits than its factorization.

172138779800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66207252 (or 66207243 counting only the distinct ones).

The product of its (nonzero) digits is 1185408, while the sum is 53.

The spelling of 172138779800 in words is "one hundred seventy-two billion, one hundred thirty-eight million, seven hundred seventy-nine thousand, eight hundred".