21884380 has 72 divisors (see below), whose sum is σ = 54181008. Its totient is φ = 7402752.

The previous prime is 21884351. The next prime is 21884383. The reversal of 21884380 is 8348812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21884383) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134179 + ... + 134341.

It is an arithmetic number, because the mean of its divisors is an integer number (752514).

Almost surely, 2^21884380 is an apocalyptic number.

21884380 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 21884380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27090504).

21884380 is an abundant number, since it is smaller than the sum of its proper divisors (32296628).

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

21884380 is a wasteful number, since it uses less digits than its factorization.

21884380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 34.

The square root of 21884380 is about 4678.0743901738. The cubic root of 21884380 is about 279.7122042929.

The spelling of 21884380 in words is "twenty-one million, eight hundred eighty-four thousand, three hundred eighty".