21459680 has 96 divisors (see below), whose sum is σ = 56337120. Its totient is φ = 7659520.

The previous prime is 21459673. The next prime is 21459701. The reversal of 21459680 is 8695412.

It is a self number, because there is not a number n which added to its sum of digits gives 21459680.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 156572 + ... + 156708.

It is an arithmetic number, because the mean of its divisors is an integer number (586845).

Almost surely, 2^21459680 is an apocalyptic number.

21459680 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 21459680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28168560).

21459680 is an abundant number, since it is smaller than the sum of its proper divisors (34877440).

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

21459680 is a wasteful number, since it uses less digits than its factorization.

21459680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252 (or 244 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 21459680 is about 4632.4593900001. The cubic root of 21459680 is about 277.8909566649.

The spelling of 21459680 in words is "twenty-one million, four hundred fifty-nine thousand, six hundred eighty".