21516733008 has 120 divisors (see below), whose sum is σ = 64425901280. Its totient is φ = 6683316480.

The previous prime is 21516733003. The next prime is 21516733033. The reversal of 21516733008 is 80033761512.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21516733003) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102435 + ... + 231357.

Almost surely, 2^21516733008 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 21516733008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32212950640).

21516733008 is an abundant number, since it is smaller than the sum of its proper divisors (42909168272).

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

21516733008 is a wasteful number, since it uses less digits than its factorization.

21516733008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129017 (or 129008 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The spelling of 21516733008 in words is "twenty-one billion, five hundred sixteen million, seven hundred thirty-three thousand, eight".