21669254644 has 12 divisors (see below), whose sum is σ = 38008776484. Its totient is φ = 10809604224.

The previous prime is 21669254627. The next prime is 21669254657. The reversal of 21669254644 is 44645296612.

It can be written as a sum of positive squares in 2 ways, for example, as 5514844644 + 16154410000 = 74262^2 + 127100^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6253827 + ... + 6257290.

Almost surely, 2^21669254644 is an apocalyptic number.

It is an amenable number.

21669254644 is a deficient number, since it is larger than the sum of its proper divisors (16339521840).

21669254644 is a wasteful number, since it uses less digits than its factorization.

21669254644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12511554 (or 12511552 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 49.

The spelling of 21669254644 in words is "twenty-one billion, six hundred sixty-nine million, two hundred fifty-four thousand, six hundred forty-four".