646604522256 has 320 divisors, whose sum is σ = 2158704691200. Its totient is φ = 161832652800.

The previous prime is 646604522251. The next prime is 646604522321. The reversal of 646604522256 is 652225406646.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (646604522251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 55837075 + ... + 55848653.

It is an arithmetic number, because the mean of its divisors is an integer number (6745952160).

Almost surely, 2^646604522256 is an apocalyptic number.

646604522256 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646604522256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1079352345600).

646604522256 is an abundant number, since it is smaller than the sum of its proper divisors (1512100168944).

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

646604522256 is a wasteful number, since it uses less digits than its factorization.

646604522256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12158 (or 12152 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 48.

The spelling of 646604522256 in words is "six hundred forty-six billion, six hundred four million, five hundred twenty-two thousand, two hundred fifty-six".