666980715 has 32 divisors (see below), whose sum is σ = 1107302400. Its totient is φ = 342419840.

The previous prime is 666980687. The next prime is 666980753. The reversal of 666980715 is 517089666.

666980715 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 666980715 - 2⁵ = 666980683 is a prime.

It is a super-2 number, since 2×666980715² = 889726548363822450, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 154030 + ... + 158300.

It is an arithmetic number, because the mean of its divisors is an integer number (34603200).

Almost surely, 2^666980715 is an apocalyptic number.

666980715 is a deficient number, since it is larger than the sum of its proper divisors (440321685).

666980715 is a wasteful number, since it uses less digits than its factorization.

666980715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4667.

The product of its (nonzero) digits is 544320, while the sum is 48.

The square root of 666980715 is about 25825.9697785001. The cubic root of 666980715 is about 873.7176164469.

Subtracting from 666980715 its reverse (517089666), we obtain a square (149891049 = 12243²).

The spelling of 666980715 in words is "six hundred sixty-six million, nine hundred eighty thousand, seven hundred fifteen".