666716680 has 64 divisors (see below), whose sum is σ = 1746800640. Its totient is φ = 224270592.

The previous prime is 666716651. The next prime is 666716683. The reversal of 666716680 is 86617666.

It is a super-2 number, since 2×666716680² = 889022262780444800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 666716680.

It is not an unprimeable number, because it can be changed into a prime (666716683) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7624 + ... + 37303.

It is an arithmetic number, because the mean of its divisors is an integer number (27293760).

Almost surely, 2^666716680 is an apocalyptic number.

It is an amenable number.

666716680 is an abundant number, since it is smaller than the sum of its proper divisors (1080083960).

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

666716680 is a wasteful number, since it uses less digits than its factorization.

666716680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44998 (or 44994 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 46.

The square root of 666716680 is about 25820.8574605879. The cubic root of 666716680 is about 873.6023095255.

The spelling of 666716680 in words is "six hundred sixty-six million, seven hundred sixteen thousand, six hundred eighty".