666665320 has 32 divisors (see below), whose sum is σ = 1500988320. Its totient is φ = 266489920.

The previous prime is 666665317. The next prime is 666665341. The reversal of 666665320 is 23566666.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a nialpdrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 67839 + ... + 77041.

It is an arithmetic number, because the mean of its divisors is an integer number (46905885).

Almost surely, 2^666665320 is an apocalyptic number.

It is an amenable number.

666665320 is an abundant number, since it is smaller than the sum of its proper divisors (834323000).

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

666665320 is a wasteful number, since it uses less digits than its factorization.

666665320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11025 (or 11021 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

The square root of 666665320 is about 25819.8628966151. The cubic root of 666665320 is about 873.5798765251.

The spelling of 666665320 in words is "six hundred sixty-six million, six hundred sixty-five thousand, three hundred twenty".