21336828 has 12 divisors (see below), whose sum is σ = 49785960. Its totient is φ = 7112272.

The previous prime is 21336803. The next prime is 21336839. The reversal of 21336828 is 82863312.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 889023 + ... + 889046.

It is an arithmetic number, because the mean of its divisors is an integer number (4148830).

Almost surely, 2^21336828 is an apocalyptic number.

It is an amenable number.

21336828 is an abundant number, since it is smaller than the sum of its proper divisors (28449132).

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

21336828 is a wasteful number, since it uses less digits than its factorization.

21336828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1778076 (or 1778074 counting only the distinct ones).

The product of its digits is 13824, while the sum is 33.

The square root of 21336828 is about 4619.1804467892. The cubic root of 21336828 is about 277.3596530792.

The spelling of 21336828 in words is "twenty-one million, three hundred thirty-six thousand, eight hundred twenty-eight".