21536228 has 12 divisors (see below), whose sum is σ = 43072512. Its totient is φ = 9229800.

The previous prime is 21536213. The next prime is 21536261. The reversal of 21536228 is 82263512.

21536228 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 21536228.

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, 384548 + ... + 384603.

It is an arithmetic number, because the mean of its divisors is an integer number (3589376).

Almost surely, 2^21536228 is an apocalyptic number.

21536228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21536228 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.

21536228 is a wasteful number, since it uses less digits than its factorization.

21536228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 769162 (or 769160 counting only the distinct ones).

The product of its digits is 5760, while the sum is 29.

The square root of 21536228 is about 4640.7141691770. The cubic root of 21536228 is about 278.2209826192.

The spelling of 21536228 in words is "twenty-one million, five hundred thirty-six thousand, two hundred twenty-eight".