21268356 has 24 divisors (see below), whose sum is σ = 51227904. Its totient is φ = 6860640.

The previous prime is 21268327. The next prime is 21268361. The reversal of 21268356 is 65386212.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28215 + ... + 28958.

It is an arithmetic number, because the mean of its divisors is an integer number (2134496).

Almost surely, 2^21268356 is an apocalyptic number.

It is an amenable number.

21268356 is an abundant number, since it is smaller than the sum of its proper divisors (29959548).

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

21268356 is a wasteful number, since it uses less digits than its factorization.

21268356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57211 (or 57209 counting only the distinct ones).

The product of its digits is 17280, while the sum is 33.

The square root of 21268356 is about 4611.7627866142. The cubic root of 21268356 is about 277.0626435843.

The spelling of 21268356 in words is "twenty-one million, two hundred sixty-eight thousand, three hundred fifty-six".