21660424204564 has 24 divisors (see below), whose sum is σ = 39901198851360. Its totient is φ = 10260093602016.

The previous prime is 21660424204499. The next prime is 21660424204619. The reversal of 21660424204564 is 46540242406612.

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, 6072534 + ... + 8955250.

It is an arithmetic number, because the mean of its divisors is an integer number (1662549952140).

Almost surely, 2^{21660424204564} is an apocalyptic number.

It is an amenable number.

21660424204564 is a deficient number, since it is larger than the sum of its proper divisors (18240774646796).

21660424204564 is a wasteful number, since it uses less digits than its factorization.

21660424204564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2981607 (or 2981605 counting only the distinct ones).

The product of its (nonzero) digits is 2211840, while the sum is 46.

The spelling of 21660424204564 in words is "twenty-one trillion, six hundred sixty billion, four hundred twenty-four million, two hundred four thousand, five hundred sixty-four".