667706872178 has 48 divisors (see below), whose sum is σ = 1082928009600. Its totient is φ = 308622362880.

The previous prime is 667706872141. The next prime is 667706872181. The reversal of 667706872178 is 871278607766.

It is a Smith number, since the sum of its digits (65) 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 23 ways as a sum of consecutive naturals, for example, 25337333 + ... + 25363671.

It is an arithmetic number, because the mean of its divisors is an integer number (22561000200).

Almost surely, 2^667706872178 is an apocalyptic number.

667706872178 is a deficient number, since it is larger than the sum of its proper divisors (415221137422).

667706872178 is a wasteful number, since it uses less digits than its factorization.

667706872178 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27155 (or 27138 counting only the distinct ones).

The product of its (nonzero) digits is 66382848, while the sum is 65.

The spelling of 667706872178 in words is "six hundred sixty-seven billion, seven hundred six million, eight hundred seventy-two thousand, one hundred seventy-eight".