666986972 has 12 divisors (see below), whose sum is σ = 1171031400. Its totient is φ = 332406576.

The previous prime is 666986953. The next prime is 666986977. The reversal of 666986972 is 279689666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666986977) 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, 270347 + ... + 272802.

It is an arithmetic number, because the mean of its divisors is an integer number (97585950).

Almost surely, 2^666986972 is an apocalyptic number.

It is an amenable number.

666986972 is a deficient number, since it is larger than the sum of its proper divisors (504044428).

666986972 is a wasteful number, since it uses less digits than its factorization.

666986972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543460 (or 543458 counting only the distinct ones).

The product of its digits is 11757312, while the sum is 59.

The square root of 666986972 is about 25826.0909159710. The cubic root of 666986972 is about 873.7203485769.

The spelling of 666986972 in words is "six hundred sixty-six million, nine hundred eighty-six thousand, nine hundred seventy-two".