64608921 has 20 divisors (see below), whose sum is σ = 103940452. Its totient is φ = 39758688.

The previous prime is 64608917. The next prime is 64608923. The reversal of 64608921 is 12980646.

64608921 is a `hidden beast` number, since 646 + 0 + 8 + 9 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 37454400 + 27154521 = 6120^2 + 5211^2 .

It is not a de Polignac number, because 64608921 - 2² = 64608917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64608923) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 29626 + ... + 31731.

Almost surely, 2^64608921 is an apocalyptic number.

It is an amenable number.

64608921 is a deficient number, since it is larger than the sum of its proper divisors (39331531).

64608921 is a wasteful number, since it uses less digits than its factorization.

64608921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61382 (or 61373 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 64608921 is about 8037.9674669658. The cubic root of 64608921 is about 401.2645832764.

The spelling of 64608921 in words is "sixty-four million, six hundred eight thousand, nine hundred twenty-one".