646426321652520 has 128 divisors (see below), whose sum is σ = 2154774286598400. Its totient is φ = 172378761954048.

The previous prime is 646426321652497. The next prime is 646426321652591. The reversal of 646426321652520 is 25256123624646.

646426321652520 is a `hidden beast` number, since 6 + 4 + 6 + 4 + 2 + 6 + 321 + 65 + 252 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 116738797 + ... + 122150723.

It is an arithmetic number, because the mean of its divisors is an integer number (16834174114050).

Almost surely, 2^{646426321652520} is an apocalyptic number.

646426321652520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

646426321652520 is an abundant number, since it is smaller than the sum of its proper divisors (1508347964945880).

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

646426321652520 is a wasteful number, since it uses less digits than its factorization.

646426321652520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5522544 (or 5522534 counting only the distinct ones).

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

The spelling of 646426321652520 in words is "six hundred forty-six trillion, four hundred twenty-six billion, three hundred twenty-one million, six hundred fifty-two thousand, five hundred twenty".