21336228 has 72 divisors (see below), whose sum is σ = 56609280. Its totient is φ = 6767040.

The previous prime is 21336223. The next prime is 21336233. The reversal of 21336228 is 82263312.

21336228 is a `hidden beast` number, since 2 + 1 + 33 + 622 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (21336223) and next prime (21336233).

It is not an unprimeable number, because it can be changed into a prime (21336223) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 111613 + ... + 111803.

It is an arithmetic number, because the mean of its divisors is an integer number (786240).

Almost surely, 2^21336228 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21336228, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28304640).

21336228 is an abundant number, since it is smaller than the sum of its proper divisors (35273052).

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

21336228 is a wasteful number, since it uses less digits than its factorization.

21336228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337 (or 332 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21336228 is about 4619.1154997467. The cubic root of 21336228 is about 277.3570532340.

The spelling of 21336228 in words is "twenty-one million, three hundred thirty-six thousand, two hundred twenty-eight".