21803264 has 72 divisors (see below), whose sum is σ = 51999360. Its totient is φ = 8937984.

The previous prime is 21803251. The next prime is 21803281. The reversal of 21803264 is 46230812.

It is a congruent number.

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, 947957 + ... + 947979.

Almost surely, 2^21803264 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 21803264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25999680).

21803264 is an abundant number, since it is smaller than the sum of its proper divisors (30196096).

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

21803264 is an frugal number, since it uses more digits than its factorization.

21803264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 32 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21803264 is about 4669.3965348854. The cubic root of 21803264 is about 279.3661854126.

The spelling of 21803264 in words is "twenty-one million, eight hundred three thousand, two hundred sixty-four".