28218790 has 32 divisors (see below), whose sum is σ = 53187840. Its totient is φ = 10767744.

The previous prime is 28218787. The next prime is 28218791. The reversal of 28218790 is 9781282.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28218791) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18891 + ... + 20329.

It is an arithmetic number, because the mean of its divisors is an integer number (1662120).

Almost surely, 2^28218790 is an apocalyptic number.

28218790 is a deficient number, since it is larger than the sum of its proper divisors (24969050).

28218790 is a wasteful number, since it uses less digits than its factorization.

28218790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1536.

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 28218790 is about 5312.1361051841. The cubic root of 28218790 is about 304.4477689898.

It can be divided in two parts, 2821 and 8790, that added together give a palindrome (11611).

The spelling of 28218790 in words is "twenty-eight million, two hundred eighteen thousand, seven hundred ninety".