21620655204 has 12 divisors (see below), whose sum is σ = 50448195504. Its totient is φ = 7206885064.

The previous prime is 21620655187. The next prime is 21620655229. The reversal of 21620655204 is 40255602612.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900860622 + ... + 900860645.

It is an arithmetic number, because the mean of its divisors is an integer number (4204016292).

Almost surely, 2^21620655204 is an apocalyptic number.

It is an amenable number.

21620655204 is an abundant number, since it is smaller than the sum of its proper divisors (28827540300).

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

21620655204 is a wasteful number, since it uses less digits than its factorization.

21620655204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801721274 (or 1801721272 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 33.

The spelling of 21620655204 in words is "twenty-one billion, six hundred twenty million, six hundred fifty-five thousand, two hundred four".