21085752988056 has 64 divisors (see below), whose sum is σ = 52815877632000. Its totient is φ = 7015064672000.

The previous prime is 21085752987997. The next prime is 21085752988057. The reversal of 21085752988056 is 65088925758012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21085752988057) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 25550281 + ... + 26362631.

It is an arithmetic number, because the mean of its divisors is an integer number (825248088000).

Almost surely, 2^{21085752988056} is an apocalyptic number.

It is an amenable number.

21085752988056 is an abundant number, since it is smaller than the sum of its proper divisors (31730124643944).

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

21085752988056 is a wasteful number, since it uses less digits than its factorization.

21085752988056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814440 (or 814436 counting only the distinct ones).

The product of its (nonzero) digits is 96768000, while the sum is 66.

The spelling of 21085752988056 in words is "twenty-one trillion, eighty-five billion, seven hundred fifty-two million, nine hundred eighty-eight thousand, fifty-six".