21621351102540 has 96 divisors (see below), whose sum is σ = 69198538913280. Its totient is φ = 4941293438976.

The previous prime is 21621351102487. The next prime is 21621351102601. The reversal of 21621351102540 is 4520115312612.

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 31 ways as a sum of consecutive naturals, for example, 949797 + ... + 6644156.

It is an arithmetic number, because the mean of its divisors is an integer number (720818113680).

Almost surely, 2^{21621351102540} is an apocalyptic number.

21621351102540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21621351102540 is an abundant number, since it is smaller than the sum of its proper divisors (47577187810740).

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

21621351102540 is a wasteful number, since it uses less digits than its factorization.

21621351102540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7600751 (or 7600749 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 33.

The spelling of 21621351102540 in words is "twenty-one trillion, six hundred twenty-one billion, three hundred fifty-one million, one hundred two thousand, five hundred forty".