21897268 has 12 divisors (see below), whose sum is σ = 39043620. Its totient is φ = 10741952.

The previous prime is 21897247. The next prime is 21897283. The reversal of 21897268 is 86279812.

It can be written as a sum of positive squares in 2 ways, for example, as 6749604 + 15147664 = 2598^2 + 3892^2 .

It is a congruent number.

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, 51433 + ... + 51856.

It is an arithmetic number, because the mean of its divisors is an integer number (3253635).

Almost surely, 2^21897268 is an apocalyptic number.

It is an amenable number.

21897268 is a deficient number, since it is larger than the sum of its proper divisors (17146352).

21897268 is a wasteful number, since it uses less digits than its factorization.

21897268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103346 (or 103344 counting only the distinct ones).

The product of its digits is 96768, while the sum is 43.

The square root of 21897268 is about 4679.4516772801. The cubic root of 21897268 is about 279.7671022529.

The spelling of 21897268 in words is "twenty-one million, eight hundred ninety-seven thousand, two hundred sixty-eight".