21368828 has 24 divisors (see below), whose sum is σ = 40397952. Its totient is φ = 9831744.

The previous prime is 21368821. The next prime is 21368843. The reversal of 21368828 is 82886312.

It is a junction number, because it is equal to n+sod(n) for n = 21368791 and 21368800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21368821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31226 + ... + 31902.

It is an arithmetic number, because the mean of its divisors is an integer number (1683248).

Almost surely, 2^21368828 is an apocalyptic number.

It is an amenable number.

21368828 is a deficient number, since it is larger than the sum of its proper divisors (19029124).

21368828 is a wasteful number, since it uses less digits than its factorization.

21368828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1301 (or 1299 counting only the distinct ones).

The product of its digits is 36864, while the sum is 38.

The square root of 21368828 is about 4622.6429669616. The cubic root of 21368828 is about 277.4982409325.

The spelling of 21368828 in words is "twenty-one million, three hundred sixty-eight thousand, eight hundred twenty-eight".