668872171 has 4 divisors (see below), whose sum is σ = 729678744. Its totient is φ = 608065600.

The previous prime is 668872103. The next prime is 668872207. The reversal of 668872171 is 171278866.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 668872171 - 2¹⁵ = 668839403 is a prime.

It is a super-2 number, since 2×668872171² = 894779962276506482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (668870171) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30403270 + ... + 30403291.

It is an arithmetic number, because the mean of its divisors is an integer number (182419686).

Almost surely, 2^668872171 is an apocalyptic number.

668872171 is a deficient number, since it is larger than the sum of its proper divisors (60806573).

668872171 is a wasteful number, since it uses less digits than its factorization.

668872171 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60806572.

The product of its digits is 225792, while the sum is 46.

The square root of 668872171 is about 25862.5631173710. The cubic root of 668872171 is about 874.5427471064.

The spelling of 668872171 in words is "six hundred sixty-eight million, eight hundred seventy-two thousand, one hundred seventy-one".