21426828 has 48 divisors (see below), whose sum is σ = 52039680. Its totient is φ = 6854400.

The previous prime is 21426827. The next prime is 21426841. The reversal of 21426828 is 82862412.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21426827) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88788 + ... + 89028.

It is an arithmetic number, because the mean of its divisors is an integer number (1084160).

Almost surely, 2^21426828 is an apocalyptic number.

It is an amenable number.

21426828 is an abundant number, since it is smaller than the sum of its proper divisors (30612852).

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

21426828 is a wasteful number, since it uses less digits than its factorization.

21426828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518 (or 516 counting only the distinct ones).

The product of its digits is 12288, while the sum is 33.

The square root of 21426828 is about 4628.9121832240. The cubic root of 21426828 is about 277.7490791803.

The spelling of 21426828 in words is "twenty-one million, four hundred twenty-six thousand, eight hundred twenty-eight".