666118657 has 2 divisors, whose sum is σ = 666118658. Its totient is φ = 666118656.

The previous prime is 666118643. The next prime is 666118697. The reversal of 666118657 is 756811666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 415181376 + 250937281 = 20376^2 + 15841^2 .

It is a cyclic number.

It is not a de Polignac number, because 666118657 - 2⁷ = 666118529 is a prime.

It is not a weakly prime, because it can be changed into another prime (666118637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333059328 + 333059329.

It is an arithmetic number, because the mean of its divisors is an integer number (333059329).

Almost surely, 2^666118657 is an apocalyptic number.

It is an amenable number.

666118657 is a deficient number, since it is larger than the sum of its proper divisors (1).

666118657 is an equidigital number, since it uses as much as digits as its factorization.

666118657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 46.

The square root of 666118657 is about 25809.2746314188. The cubic root of 666118657 is about 873.3410338494.

The spelling of 666118657 in words is "six hundred sixty-six million, one hundred eighteen thousand, six hundred fifty-seven".