21268288 has 14 divisors (see below), whose sum is σ = 42204386. Its totient is φ = 10634112.

The previous prime is 21268271. The next prime is 21268297. The reversal of 21268288 is 88286212.

It can be written as a sum of positive squares in only one way, i.e., 16908544 + 4359744 = 4112^2 + 2088^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166095 + ... + 166222.

It is an arithmetic number, because the mean of its divisors is an integer number (3014599).

Almost surely, 2^21268288 is an apocalyptic number.

It is an amenable number.

21268288 is a deficient number, since it is larger than the sum of its proper divisors (20936098).

21268288 is an equidigital number, since it uses as much as digits as its factorization.

21268288 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332329 (or 332319 counting only the distinct ones).

The product of its digits is 24576, while the sum is 37.

The square root of 21268288 is about 4611.7554141563. The cubic root of 21268288 is about 277.0623483055.

The spelling of 21268288 in words is "twenty-one million, two hundred sixty-eight thousand, two hundred eighty-eight".