21664252544046 has 64 divisors (see below), whose sum is σ = 51532560737280. Its totient is φ = 5940558973440.

The previous prime is 21664252543993. The next prime is 21664252544059. The reversal of 21664252544046 is 64044525246612.

It is a self number, because there is not a number n which added to its sum of digits gives 21664252544046.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 53050315 + ... + 53457126.

It is an arithmetic number, because the mean of its divisors is an integer number (805196261520).

Almost surely, 2^{21664252544046} is an apocalyptic number.

21664252544046 is an abundant number, since it is smaller than the sum of its proper divisors (29868308193234).

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

21664252544046 is a wasteful number, since it uses less digits than its factorization.

21664252544046 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106507649.

The product of its (nonzero) digits is 11059200, while the sum is 51.

The spelling of 21664252544046 in words is "twenty-one trillion, six hundred sixty-four billion, two hundred fifty-two million, five hundred forty-four thousand, forty-six".