21680084160 has 280 divisors, whose sum is σ = 88137735840. Its totient is φ = 4955406336.

The previous prime is 21680084149. The next prime is 21680084183. The reversal of 21680084160 is 6148008612.

It is a tau number, because it is divible by the number of its divisors (280).

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 39 ways as a sum of consecutive naturals, for example, 121696 + ... + 241184.

It is an arithmetic number, because the mean of its divisors is an integer number (314777628).

Almost surely, 2^21680084160 is an apocalyptic number.

21680084160 is a gapful number since it is divisible by the number (20) 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 21680084160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44068867920).

21680084160 is an abundant number, since it is smaller than the sum of its proper divisors (66457651680).

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

21680084160 is a wasteful number, since it uses less digits than its factorization.

21680084160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119525 (or 119506 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 21680084160 in words is "twenty-one billion, six hundred eighty million, eighty-four thousand, one hundred sixty".