646470864 has 120 divisors (see below), whose sum is σ = 1962152192. Its totient is φ = 197510400.

The previous prime is 646470857. The next prime is 646470887. The reversal of 646470864 is 468074646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 281529 + ... + 283815.

Almost surely, 2^646470864 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 646470864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (981076096).

646470864 is an abundant number, since it is smaller than the sum of its proper divisors (1315681328).

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

646470864 is a wasteful number, since it uses less digits than its factorization.

646470864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2465 (or 2456 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 45.

The square root of 646470864 is about 25425.7913151194. The cubic root of 646470864 is about 864.6685283682.

The spelling of 646470864 in words is "six hundred forty-six million, four hundred seventy thousand, eight hundred sixty-four".