21066532416 has 336 divisors, whose sum is σ = 66948710400. Its totient is φ = 6303661056.

The previous prime is 21066532387. The next prime is 21066532433. The reversal of 21066532416 is 61423566012.

21066532416 is a `hidden beast` number, since 2 + 106 + 6 + 532 + 4 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31967095 + ... + 31967753.

Almost surely, 2^21066532416 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 21066532416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33474355200).

21066532416 is an abundant number, since it is smaller than the sum of its proper divisors (45882177984).

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

21066532416 is a wasteful number, since it uses less digits than its factorization.

21066532416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 846 (or 833 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The spelling of 21066532416 in words is "twenty-one billion, sixty-six million, five hundred thirty-two thousand, four hundred sixteen".