668974881 has 4 divisors (see below), whose sum is σ = 891966512. Its totient is φ = 445983252.

The previous prime is 668974879. The next prime is 668974907. The reversal of 668974881 is 188479866.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 668974881 - 2¹ = 668974879 is a prime.

It is a super-2 number, since 2×668974881² = 895054782817928322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (668974811) 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, 111495811 + ... + 111495816.

It is an arithmetic number, because the mean of its divisors is an integer number (222991628).

Almost surely, 2^668974881 is an apocalyptic number.

It is an amenable number.

668974881 is a deficient number, since it is larger than the sum of its proper divisors (222991631).

668974881 is a wasteful number, since it uses less digits than its factorization.

668974881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222991630.

The product of its digits is 4644864, while the sum is 57.

The square root of 668974881 is about 25864.5487298735. The cubic root of 668974881 is about 874.5875088671.

The spelling of 668974881 in words is "six hundred sixty-eight million, nine hundred seventy-four thousand, eight hundred eighty-one".