21655362666204 has 18 divisors (see below), whose sum is σ = 54739944517440. Its totient is φ = 7218454222056.

The previous prime is 21655362666199. The next prime is 21655362666211. The reversal of 21655362666204 is 40266626355612.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

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 5 ways as a sum of consecutive naturals, for example, 300768925884 + ... + 300768925955.

Almost surely, 2^{21655362666204} is an apocalyptic number.

It is an amenable number.

21655362666204 is an abundant number, since it is smaller than the sum of its proper divisors (33084581851236).

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

21655362666204 is a wasteful number, since it uses less digits than its factorization.

21655362666204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601537851849 (or 601537851844 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 54.

The spelling of 21655362666204 in words is "twenty-one trillion, six hundred fifty-five billion, three hundred sixty-two million, six hundred sixty-six thousand, two hundred four".