64646656 has 40 divisors (see below), whose sum is σ = 133366464. Its totient is φ = 31272960.

The previous prime is 64646653. The next prime is 64646669. The reversal of 64646656 is 65664646.

It is a congruent number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13836 + ... + 17908.

Almost surely, 2^64646656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64646656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66683232).

64646656 is an abundant number, since it is smaller than the sum of its proper divisors (68719808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64646656 is an equidigital number, since it uses as much as digits as its factorization.

64646656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4122 (or 4106 counting only the distinct ones).

The product of its digits is 622080, while the sum is 43.

The square root of 64646656 is about 8040.3144217126. The cubic root of 64646656 is about 401.3426879299.

The spelling of 64646656 in words is "sixty-four million, six hundred forty-six thousand, six hundred fifty-six".