668172894 has 32 divisors (see below), whose sum is σ = 1361531904. Its totient is φ = 218544480.

The previous prime is 668172881. The next prime is 668172937. The reversal of 668172894 is 498271866.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 167487 + ... + 171429.

It is an arithmetic number, because the mean of its divisors is an integer number (42547872).

Almost surely, 2^668172894 is an apocalyptic number.

668172894 is an abundant number, since it is smaller than the sum of its proper divisors (693359010).

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

668172894 is a wasteful number, since it uses less digits than its factorization.

668172894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4472.

The product of its digits is 1161216, while the sum is 51.

The square root of 668172894 is about 25849.0404850934. The cubic root of 668172894 is about 874.2378752667.

The spelling of 668172894 in words is "six hundred sixty-eight million, one hundred seventy-two thousand, eight hundred ninety-four".