21983880 has 64 divisors (see below), whose sum is σ = 66407040. Its totient is φ = 5821952.

The previous prime is 21983869. The next prime is 21983881. The reversal of 21983880 is 8838912.

It is not an unprimeable number, because it can be changed into a prime (21983881) 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, 19492 + ... + 20588.

It is an arithmetic number, because the mean of its divisors is an integer number (1037610).

Almost surely, 2^21983880 is an apocalyptic number.

21983880 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 21983880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33203520).

21983880 is an abundant number, since it is smaller than the sum of its proper divisors (44423160).

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

21983880 is a wasteful number, since it uses less digits than its factorization.

21983880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1278 (or 1274 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 39.

The square root of 21983880 is about 4688.6970471550. The cubic root of 21983880 is about 280.1354786555.

The spelling of 21983880 in words is "twenty-one million, nine hundred eighty-three thousand, eight hundred eighty".