64646657 has 4 divisors (see below), whose sum is σ = 64710996. Its totient is φ = 64582320.

The previous prime is 64646653. The next prime is 64646669. The reversal of 64646657 is 75664646.

64646657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18284176 + 46362481 = 4276^2 + 6809^2 .

It is a cyclic number.

It is not a de Polignac number, because 64646657 - 2² = 64646653 is a prime.

It is a super-2 number, since 2×64646657² = 8358380522551298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64646651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30638 + ... + 32679.

It is an arithmetic number, because the mean of its divisors is an integer number (16177749).

Almost surely, 2^64646657 is an apocalyptic number.

It is an amenable number.

64646657 is a deficient number, since it is larger than the sum of its proper divisors (64339).

64646657 is a wasteful number, since it uses less digits than its factorization.

64646657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64338.

The product of its digits is 725760, while the sum is 44.

The square root of 64646657 is about 8040.3144838992. The cubic root of 64646657 is about 401.3426899993.

The spelling of 64646657 in words is "sixty-four million, six hundred forty-six thousand, six hundred fifty-seven".