646520398560 has 144 divisors (see below), whose sum is σ = 2336030410896. Its totient is φ = 162263937024.

The previous prime is 646520398523. The next prime is 646520398583. The reversal of 646520398560 is 65893025646.

646520398560 is a `hidden beast` number, since 6 + 4 + 6 + 520 + 39 + 85 + 6 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 646520398497 and 646520398506.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13180594 + ... + 13229553.

It is an arithmetic number, because the mean of its divisors is an integer number (16222433409).

Almost surely, 2^646520398560 is an apocalyptic number.

646520398560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646520398560 is an abundant number, since it is smaller than the sum of its proper divisors (1689510012336).

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

646520398560 is a wasteful number, since it uses less digits than its factorization.

646520398560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26410185 (or 26410174 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 54.

The spelling of 646520398560 in words is "six hundred forty-six billion, five hundred twenty million, three hundred ninety-eight thousand, five hundred sixty".