668379966 has 16 divisors (see below), whose sum is σ = 1359417600. Its totient is φ = 219017048.

The previous prime is 668379961. The next prime is 668380039. The reversal of 668379966 is 669973866.

It is a super-2 number, since 2×668379966² = 893463557900322312, which contains 22 as substring.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668379961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 943686 + ... + 944393.

It is an arithmetic number, because the mean of its divisors is an integer number (84963600).

Almost surely, 2^668379966 is an apocalyptic number.

668379966 is an abundant number, since it is smaller than the sum of its proper divisors (691037634).

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

668379966 is a wasteful number, since it uses less digits than its factorization.

668379966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1888143.

The product of its digits is 17635968, while the sum is 60.

The square root of 668379966 is about 25853.0455846115. The cubic root of 668379966 is about 874.3281769881.

The spelling of 668379966 in words is "six hundred sixty-eight million, three hundred seventy-nine thousand, nine hundred sixty-six".