21640663025652 has 96 divisors (see below), whose sum is σ = 57986596039680. Its totient is φ = 6212411493120.

The previous prime is 21640663025651. The next prime is 21640663025659. The reversal of 21640663025652 is 25652036604612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21640663025651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 79259473 + ... + 79532039.

It is an arithmetic number, because the mean of its divisors is an integer number (604027042080).

Almost surely, 2^{21640663025652} is an apocalyptic number.

21640663025652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21640663025652 is an abundant number, since it is smaller than the sum of its proper divisors (36345933014028).

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

21640663025652 is a wasteful number, since it uses less digits than its factorization.

21640663025652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304261 (or 304259 counting only the distinct ones).

The product of its (nonzero) digits is 3110400, while the sum is 48.

The spelling of 21640663025652 in words is "twenty-one trillion, six hundred forty billion, six hundred sixty-three million, twenty-five thousand, six hundred fifty-two".