21002335085664 has 192 divisors, whose sum is σ = 62705350471680. Its totient is φ = 6835922426880.

The previous prime is 21002335085657. The next prime is 21002335085671. The reversal of 21002335085664 is 46658053320012.

21002335085664 is a `hidden beast` number, since 2 + 1 + 0 + 0 + 2 + 33 + 50 + 8 + 566 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (21002335085657) and next prime (21002335085671).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16902052 + ... + 18102044.

It is an arithmetic number, because the mean of its divisors is an integer number (326590367040).

Almost surely, 2^{21002335085664} is an apocalyptic number.

21002335085664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21002335085664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31352675235840).

21002335085664 is an abundant number, since it is smaller than the sum of its proper divisors (41703015386016).

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

21002335085664 is a wasteful number, since it uses less digits than its factorization.

21002335085664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1200490 (or 1200476 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 21002335085664 in words is "twenty-one trillion, two billion, three hundred thirty-five million, eighty-five thousand, six hundred sixty-four".