521655561012 has 24 divisors (see below), whose sum is σ = 1288796092416. Its totient is φ = 163656646528.

The previous prime is 521655560977. The next prime is 521655561067. The reversal of 521655561012 is 210165556125.

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 7 ways as a sum of consecutive naturals, for example, 1278567348 + ... + 1278567755.

It is an arithmetic number, because the mean of its divisors is an integer number (53699837184).

Almost surely, 2^521655561012 is an apocalyptic number.

It is an amenable number.

521655561012 is an abundant number, since it is smaller than the sum of its proper divisors (767140531404).

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

521655561012 is a wasteful number, since it uses less digits than its factorization.

521655561012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2557135127 (or 2557135125 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 39.

The spelling of 521655561012 in words is "five hundred twenty-one billion, six hundred fifty-five million, five hundred sixty-one thousand, twelve".