172118856618 has 24 divisors (see below), whose sum is σ = 374123314656. Its totient is φ = 57188471400.

The previous prime is 172118856617. The next prime is 172118856631. The reversal of 172118856618 is 816658811271.

172118856618 is a `hidden beast` number, since 1 + 7 + 2 + 1 + 18 + 8 + 5 + 6 + 618 = 666.

It is not an unprimeable number, because it can be changed into a prime (172118856617) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15367648 + ... + 15378843.

It is an arithmetic number, because the mean of its divisors is an integer number (15588471444).

Almost surely, 2^172118856618 is an apocalyptic number.

172118856618 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

172118856618 is an abundant number, since it is smaller than the sum of its proper divisors (202004458038).

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

172118856618 is a wasteful number, since it uses less digits than its factorization.

172118856618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30746810 (or 30746807 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 54.

The spelling of 172118856618 in words is "one hundred seventy-two billion, one hundred eighteen million, eight hundred fifty-six thousand, six hundred eighteen".