21660502908928 has 224 divisors, whose sum is σ = 48300774762240. Its totient is φ = 9645462650880.

The previous prime is 21660502908899. The next prime is 21660502908953. The reversal of 21660502908928 is 82980920506612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1112553978 + ... + 1112573446.

It is an arithmetic number, because the mean of its divisors is an integer number (215628458760).

Almost surely, 2^{21660502908928} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21660502908928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24150387381120).

21660502908928 is an abundant number, since it is smaller than the sum of its proper divisors (26640271853312).

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

21660502908928 is a wasteful number, since it uses less digits than its factorization.

21660502908928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19876 (or 19852 counting only the distinct ones).

The product of its (nonzero) digits is 7464960, while the sum is 58.

The spelling of 21660502908928 in words is "twenty-one trillion, six hundred sixty billion, five hundred two million, nine hundred eight thousand, nine hundred twenty-eight".