28218868 has 12 divisors (see below), whose sum is σ = 49420420. Its totient is φ = 14098752.

The previous prime is 28218833. The next prime is 28218877. The reversal of 28218868 is 86881282.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14837904 + 13380964 = 3852^2 + 3658^2 .

It is a super-2 number, since 2×28218868² = 1592609022402848, which contains 22 as substring.

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

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, 8080 + ... + 11032.

Almost surely, 2^28218868 is an apocalyptic number.

It is an amenable number.

28218868 is a deficient number, since it is larger than the sum of its proper divisors (21201552).

28218868 is a wasteful number, since it uses less digits than its factorization.

28218868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5346 (or 5344 counting only the distinct ones).

The product of its digits is 98304, while the sum is 43.

The square root of 28218868 is about 5312.1434468583. The cubic root of 28218868 is about 304.4480494992.

The spelling of 28218868 in words is "twenty-eight million, two hundred eighteen thousand, eight hundred sixty-eight".