21665083392 has 208 divisors, whose sum is σ = 64542458880. Its totient is φ = 7181549568.

The previous prime is 21665083369. The next prime is 21665083439. The reversal of 21665083392 is 29338056612.

21665083392 is a `hidden beast` number, since 21 + 6 + 6 + 508 + 33 + 92 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25103953 + ... + 25104815.

Almost surely, 2^21665083392 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 21665083392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32271229440).

21665083392 is an abundant number, since it is smaller than the sum of its proper divisors (42877375488).

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

21665083392 is an equidigital number, since it uses as much as digits as its factorization.

21665083392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1123 (or 1095 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 45.

The spelling of 21665083392 in words is "twenty-one billion, six hundred sixty-five million, eighty-three thousand, three hundred ninety-two".