21889824 has 96 divisors (see below), whose sum is σ = 66044160. Its totient is φ = 6278400.

The previous prime is 21889823. The next prime is 21889841. The reversal of 21889824 is 42898812.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21889823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19519 + ... + 20609.

It is an arithmetic number, because the mean of its divisors is an integer number (687960).

Almost surely, 2^21889824 is an apocalyptic number.

21889824 is a gapful number since it is divisible by the number (24) 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 21889824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33022080).

21889824 is an abundant number, since it is smaller than the sum of its proper divisors (44154336).

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

21889824 is a wasteful number, since it uses less digits than its factorization.

21889824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1134 (or 1126 counting only the distinct ones).

The product of its digits is 73728, while the sum is 42.

The square root of 21889824 is about 4678.6562173342. The cubic root of 21889824 is about 279.7353962832.

The spelling of 21889824 in words is "twenty-one million, eight hundred eighty-nine thousand, eight hundred twenty-four".