646252864 has 28 divisors (see below), whose sum is σ = 1298651200. Its totient is φ = 319033728.

The previous prime is 646252861. The next prime is 646252889. The reversal of 646252864 is 468252646.

It is a self number, because there is not a number n which added to its sum of digits gives 646252864.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646252861) 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, 58854 + ... + 68965.

It is an arithmetic number, because the mean of its divisors is an integer number (46380400).

Almost surely, 2^646252864 is an apocalyptic number.

646252864 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

646252864 is an abundant number, since it is smaller than the sum of its proper divisors (652398336).

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

646252864 is a wasteful number, since it uses less digits than its factorization.

646252864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 127910 (or 127900 counting only the distinct ones).

The product of its digits is 552960, while the sum is 43.

The square root of 646252864 is about 25421.5039680976. The cubic root of 646252864 is about 864.5713242291.

The spelling of 646252864 in words is "six hundred forty-six million, two hundred fifty-two thousand, eight hundred sixty-four".