664756601 has 2 divisors, whose sum is σ = 664756602. Its totient is φ = 664756600.

The previous prime is 664756583. The next prime is 664756621. The reversal of 664756601 is 106657466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 615040000 + 49716601 = 24800^2 + 7051^2 .

It is a cyclic number.

It is not a de Polignac number, because 664756601 - 2⁶ = 664756537 is a prime.

It is not a weakly prime, because it can be changed into another prime (664756621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332378300 + 332378301.

It is an arithmetic number, because the mean of its divisors is an integer number (332378301).

Almost surely, 2^664756601 is an apocalyptic number.

It is an amenable number.

664756601 is a deficient number, since it is larger than the sum of its proper divisors (1).

664756601 is an equidigital number, since it uses as much as digits as its factorization.

664756601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 181440, while the sum is 41.

The square root of 664756601 is about 25782.8741803547. The cubic root of 664756601 is about 872.7453686572.

The spelling of 664756601 in words is "six hundred sixty-four million, seven hundred fifty-six thousand, six hundred one".