21298972636560 has 80 divisors (see below), whose sum is σ = 66028560598080. Its totient is φ = 5679575892480.

The previous prime is 21298972636549. The next prime is 21298972636573. The reversal of 21298972636560 is 6563627989212.

It is a Cunningham number, because it is equal to 4615081²-1.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 21298972636491 and 21298972636500.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8076390 + ... + 10383930.

It is an arithmetic number, because the mean of its divisors is an integer number (825357007476).

Almost surely, 2^{21298972636560} is an apocalyptic number.

21298972636560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21298972636560 is an abundant number, since it is smaller than the sum of its proper divisors (44729587961520).

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

21298972636560 is a wasteful number, since it uses less digits than its factorization.

21298972636560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2346016 (or 2346010 counting only the distinct ones).

The product of its (nonzero) digits is 117573120, while the sum is 66.

The spelling of 21298972636560 in words is "twenty-one trillion, two hundred ninety-eight billion, nine hundred seventy-two million, six hundred thirty-six thousand, five hundred sixty".