21264216664444 has 24 divisors (see below), whose sum is σ = 40091491783728. Its totient is φ = 9810183171840.

The previous prime is 21264216664433. The next prime is 21264216664501. The reversal of 21264216664444 is 44446661246212.

It is a Harshad number since it is a multiple of its sum of digits (52).

It is a junction number, because it is equal to n+sod(n) for n = 21264216664391 and 21264216664400.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 84679117 + ... + 84929860.

It is an arithmetic number, because the mean of its divisors is an integer number (1670478824322).

Almost surely, 2^{21264216664444} is an apocalyptic number.

It is an amenable number.

21264216664444 is a deficient number, since it is larger than the sum of its proper divisors (18827275119284).

21264216664444 is a wasteful number, since it uses less digits than its factorization.

21264216664444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169611405 (or 169611403 counting only the distinct ones).

The product of its digits is 10616832, while the sum is 52.

The spelling of 21264216664444 in words is "twenty-one trillion, two hundred sixty-four billion, two hundred sixteen million, six hundred sixty-four thousand, four hundred forty-four".