666973660 has 12 divisors (see below), whose sum is σ = 1400644728. Its totient is φ = 266789456.

The previous prime is 666973651. The next prime is 666973661. The reversal of 666973660 is 66379666.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666973661) 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, 16674322 + ... + 16674361.

It is an arithmetic number, because the mean of its divisors is an integer number (116720394).

Almost surely, 2^666973660 is an apocalyptic number.

It is an amenable number.

666973660 is an abundant number, since it is smaller than the sum of its proper divisors (733671068).

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

666973660 is a wasteful number, since it uses less digits than its factorization.

666973660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33348692 (or 33348690 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 49.

The square root of 666973660 is about 25825.8331908188. The cubic root of 666973660 is about 873.7145358483.

The spelling of 666973660 in words is "six hundred sixty-six million, nine hundred seventy-three thousand, six hundred sixty".