646676064 has 72 divisors (see below), whose sum is σ = 1842160320. Its totient is φ = 215186688.

The previous prime is 646676057. The next prime is 646676087. The reversal of 646676064 is 460676646.

646676064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 202609 + ... + 205775.

It is an arithmetic number, because the mean of its divisors is an integer number (25585560).

Almost surely, 2^646676064 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 646676064, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (921080160).

646676064 is an abundant number, since it is smaller than the sum of its proper divisors (1195484256).

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

646676064 is a wasteful number, since it uses less digits than its factorization.

646676064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3892 (or 3881 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 45.

The square root of 646676064 is about 25429.8262675937. The cubic root of 646676064 is about 864.7600051447.

The spelling of 646676064 in words is "six hundred forty-six million, six hundred seventy-six thousand, sixty-four".