21828884 has 72 divisors (see below), whose sum is σ = 50944320. Its totient is φ = 7983360.

The previous prime is 21828881. The next prime is 21828899. The reversal of 21828884 is 48882812.

It is a super-3 number, since 3×21828884³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21828881) 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, 57407 + ... + 57785.

It is an arithmetic number, because the mean of its divisors is an integer number (707560).

Almost surely, 2^21828884 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21828884, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25472160).

21828884 is an abundant number, since it is smaller than the sum of its proper divisors (29115436).

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

21828884 is a wasteful number, since it uses less digits than its factorization.

21828884 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 416 counting only the distinct ones).

The product of its digits is 65536, while the sum is 41.

The square root of 21828884 is about 4672.1391246409. The cubic root of 21828884 is about 279.4755659786.

The spelling of 21828884 in words is "twenty-one million, eight hundred twenty-eight thousand, eight hundred eighty-four".