664625057 has 2 divisors, whose sum is σ = 664625058. Its totient is φ = 664625056.

The previous prime is 664625023. The next prime is 664625063. The reversal of 664625057 is 750526466.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 664041361 + 583696 = 25769^2 + 764^2 .

It is a cyclic number.

It is not a de Polignac number, because 664625057 - 2¹⁴ = 664608673 is a prime.

It is not a weakly prime, because it can be changed into another prime (664625077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332312528 + 332312529.

It is an arithmetic number, because the mean of its divisors is an integer number (332312529).

Almost surely, 2^664625057 is an apocalyptic number.

It is an amenable number.

664625057 is a deficient number, since it is larger than the sum of its proper divisors (1).

664625057 is an equidigital number, since it uses as much as digits as its factorization.

664625057 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 302400, while the sum is 41.

The square root of 664625057 is about 25780.3230584878. The cubic root of 664625057 is about 872.6877977157.

The spelling of 664625057 in words is "six hundred sixty-four million, six hundred twenty-five thousand, fifty-seven".