28218556 has 12 divisors (see below), whose sum is σ = 50975680. Its totient is φ = 13654080.

The previous prime is 28218527. The next prime is 28218559. The reversal of 28218556 is 65581282.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28218559) 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, 113661 + ... + 113908.

Almost surely, 2^28218556 is an apocalyptic number.

It is an amenable number.

28218556 is a deficient number, since it is larger than the sum of its proper divisors (22757124).

28218556 is a wasteful number, since it uses less digits than its factorization.

28218556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227604 (or 227602 counting only the distinct ones).

The product of its digits is 38400, while the sum is 37.

The square root of 28218556 is about 5312.1140801003. The cubic root of 28218556 is about 304.4469274587.

The spelling of 28218556 in words is "twenty-eight million, two hundred eighteen thousand, five hundred fifty-six".