21255556266664 has 64 divisors (see below), whose sum is σ = 40285071360000. Its totient is φ = 10513543423680.

The previous prime is 21255556266649. The next prime is 21255556266673. The reversal of 21255556266664 is 46666265555212.

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, 619985667 + ... + 620019949.

It is an arithmetic number, because the mean of its divisors is an integer number (629454240000).

Almost surely, 2^{21255556266664} is an apocalyptic number.

It is an amenable number.

21255556266664 is a deficient number, since it is larger than the sum of its proper divisors (19029515093336).

21255556266664 is a wasteful number, since it uses less digits than its factorization.

21255556266664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36718 (or 36714 counting only the distinct ones).

The product of its digits is 155520000, while the sum is 61.

The spelling of 21255556266664 in words is "twenty-one trillion, two hundred fifty-five billion, five hundred fifty-six million, two hundred sixty-six thousand, six hundred sixty-four".