172991660 has 24 divisors (see below), whose sum is σ = 384652800. Its totient is φ = 65126144.

The previous prime is 172991659. The next prime is 172991683. The reversal of 172991660 is 66199271.

172991660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×172991660² = 59852228859111200, which contains 22 as substring.

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, 254060 + ... + 254739.

It is an arithmetic number, because the mean of its divisors is an integer number (16027200).

Almost surely, 2^172991660 is an apocalyptic number.

172991660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

172991660 is an abundant number, since it is smaller than the sum of its proper divisors (211661140).

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

172991660 is a wasteful number, since it uses less digits than its factorization.

172991660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508825 (or 508823 counting only the distinct ones).

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 172991660 is about 13152.6293949157. The cubic root of 172991660 is about 557.1965114728.

The spelling of 172991660 in words is "one hundred seventy-two million, nine hundred ninety-one thousand, six hundred sixty".