21666364556104 has 64 divisors (see below), whose sum is σ = 44498551910400. Its totient is φ = 9844086604800.

The previous prime is 21666364556047. The next prime is 21666364556147. The reversal of 21666364556104 is 40165546366612.

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, 289732239 + ... + 289807009.

It is an arithmetic number, because the mean of its divisors is an integer number (695289873600).

Almost surely, 2^{21666364556104} is an apocalyptic number.

It is an amenable number.

21666364556104 is an abundant number, since it is smaller than the sum of its proper divisors (22832187354296).

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

21666364556104 is a wasteful number, since it uses less digits than its factorization.

21666364556104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148294 (or 148290 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 55.

The spelling of 21666364556104 in words is "twenty-one trillion, six hundred sixty-six billion, three hundred sixty-four million, five hundred fifty-six thousand, one hundred four".