21338828 has 12 divisors (see below), whose sum is σ = 42677712. Its totient is φ = 9145200.

The previous prime is 21338813. The next prime is 21338831. The reversal of 21338828 is 82883312.

It is a happy number.

21338828 is an admirable number.

It is a plaindrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381023 + ... + 381078.

It is an arithmetic number, because the mean of its divisors is an integer number (3556476).

Almost surely, 2^21338828 is an apocalyptic number.

21338828 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21338828 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21338828 is a wasteful number, since it uses less digits than its factorization.

21338828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 762112 (or 762110 counting only the distinct ones).

The product of its digits is 18432, while the sum is 35.

The square root of 21338828 is about 4619.3969303363. The cubic root of 21338828 is about 277.3683188780.

The spelling of 21338828 in words is "twenty-one million, three hundred thirty-eight thousand, eight hundred twenty-eight".