646213015344564 has 72 divisors (see below), whose sum is σ = 1694042444902080. Its totient is φ = 215396686257984.

The previous prime is 646213015344451. The next prime is 646213015344587. The reversal of 646213015344564 is 465443510312646.

646213015344564 is a `hidden beast` number, since 6 + 4 + 6 + 2 + 1 + 3 + 0 + 1 + 534 + 45 + 64 = 666.

646213015344564 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×646213015344564² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 646213015344564.

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, 15599032 + ... + 39188720.

Almost surely, 2^{646213015344564} is an apocalyptic number.

It is an amenable number.

646213015344564 is an abundant number, since it is smaller than the sum of its proper divisors (1047829429557516).

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

646213015344564 is a wasteful number, since it uses less digits than its factorization.

646213015344564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23617891 (or 23617877 counting only the distinct ones).

The product of its (nonzero) digits is 24883200, while the sum is 54.

The spelling of 646213015344564 in words is "six hundred forty-six trillion, two hundred thirteen billion, fifteen million, three hundred forty-four thousand, five hundred sixty-four".