21487268 has 12 divisors (see below), whose sum is σ = 41021232. Its totient is φ = 9766920.

The previous prime is 21487261. The next prime is 21487273. The reversal of 21487268 is 86278412.

It is a super-2 number, since 2×21487268² = 923405372207648, which contains 22 as substring.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21487261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 244130 + ... + 244217.

It is an arithmetic number, because the mean of its divisors is an integer number (3418436).

Almost surely, 2^21487268 is an apocalyptic number.

It is an amenable number.

21487268 is a deficient number, since it is larger than the sum of its proper divisors (19533964).

21487268 is a wasteful number, since it uses less digits than its factorization.

21487268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488362 (or 488360 counting only the distinct ones).

The product of its digits is 43008, while the sum is 38.

The square root of 21487268 is about 4635.4361175622. The cubic root of 21487268 is about 278.0099887721.

The spelling of 21487268 in words is "twenty-one million, four hundred eighty-seven thousand, two hundred sixty-eight".