666656057 has 2 divisors, whose sum is σ = 666656058. Its totient is φ = 666656056.

The previous prime is 666656051. The next prime is 666656113. The reversal of 666656057 is 750656666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 599809081 + 66846976 = 24491^2 + 8176^2 .

It is a cyclic number.

It is not a de Polignac number, because 666656057 - 2⁴ = 666656041 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (666656051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333328028 + 333328029.

It is an arithmetic number, because the mean of its divisors is an integer number (333328029).

Almost surely, 2^666656057 is an apocalyptic number.

It is an amenable number.

666656057 is a deficient number, since it is larger than the sum of its proper divisors (1).

666656057 is an equidigital number, since it uses as much as digits as its factorization.

666656057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1360800, while the sum is 47.

The square root of 666656057 is about 25819.6835185871. The cubic root of 666656057 is about 873.5758305129.

The spelling of 666656057 in words is "six hundred sixty-six million, six hundred fifty-six thousand, fifty-seven".