172779865880 has 32 divisors (see below), whose sum is σ = 388792364400. Its totient is φ = 69105250176.

The previous prime is 172779865847. The next prime is 172779865933. The reversal of 172779865880 is 88568977271.

It is a self number, because there is not a number n which added to its sum of digits gives 172779865880.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 219599 + ... + 627521.

Almost surely, 2^172779865880 is an apocalyptic number.

172779865880 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172779865880 is an abundant number, since it is smaller than the sum of its proper divisors (216012498520).

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

172779865880 is a wasteful number, since it uses less digits than its factorization.

172779865880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418523 (or 418519 counting only the distinct ones).

The product of its (nonzero) digits is 94832640, while the sum is 68.

The spelling of 172779865880 in words is "one hundred seventy-two billion, seven hundred seventy-nine million, eight hundred sixty-five thousand, eight hundred eighty".