21984480 has 192 divisors, whose sum is σ = 88058880. Its totient is φ = 5018112.

The previous prime is 21984467. The next prime is 21984493. The reversal of 21984480 is 8448912.

It is an interprime number because it is at equal distance from previous prime (21984467) and next prime (21984493).

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

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 31 ways as a sum of consecutive naturals, for example, 29877 + ... + 30603.

It is an arithmetic number, because the mean of its divisors is an integer number (458640).

Almost surely, 2^21984480 is an apocalyptic number.

21984480 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 21984480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44029440).

21984480 is an abundant number, since it is smaller than the sum of its proper divisors (66074400).

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

21984480 is a wasteful number, since it uses less digits than its factorization.

21984480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758 (or 744 counting only the distinct ones).

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

The square root of 21984480 is about 4688.7610303789. The cubic root of 21984480 is about 280.1380271858.

The spelling of 21984480 in words is "twenty-one million, nine hundred eighty-four thousand, four hundred eighty".