21828716 has 54 divisors (see below), whose sum is σ = 48191220. Its totient is φ = 8622432.

The previous prime is 21828707. The next prime is 21828733. The reversal of 21828716 is 61782812.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 32795 + ... + 33453.

It is an arithmetic number, because the mean of its divisors is an integer number (892430).

Almost surely, 2^21828716 is an apocalyptic number.

21828716 is a gapful number since it is divisible by the number (26) 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 21828716, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24095610).

21828716 is an abundant number, since it is smaller than the sum of its proper divisors (26362504).

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

21828716 is a wasteful number, since it uses less digits than its factorization.

21828716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 703 (or 681 counting only the distinct ones).

The product of its digits is 10752, while the sum is 35.

The square root of 21828716 is about 4672.1211456896. The cubic root of 21828716 is about 279.4748490078.

The spelling of 21828716 in words is "twenty-one million, eight hundred twenty-eight thousand, seven hundred sixteen".