21883440 has 80 divisors (see below), whose sum is σ = 71424000. Its totient is φ = 5527296.

The previous prime is 21883439. The next prime is 21883447. The reversal of 21883440 is 4438812.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21883398 and 21883407.

It is not an unprimeable number, because it can be changed into a prime (21883447) 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, 2161 + ... + 6959.

It is an arithmetic number, because the mean of its divisors is an integer number (892800).

Almost surely, 2^21883440 is an apocalyptic number.

21883440 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 21883440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35712000).

21883440 is an abundant number, since it is smaller than the sum of its proper divisors (49540560).

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

21883440 is a wasteful number, since it uses less digits than its factorization.

21883440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4834 (or 4828 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 30.

The square root of 21883440 is about 4677.9739204061. The cubic root of 21883440 is about 279.7081994085.

The spelling of 21883440 in words is "twenty-one million, eight hundred eighty-three thousand, four hundred forty".