28218099 has 24 divisors (see below), whose sum is σ = 46566912. Its totient is φ = 14882400.

The previous prime is 28218061. The next prime is 28218103. The reversal of 28218099 is 99081282.

It is not a de Polignac number, because 28218099 - 2⁷ = 28217971 is a prime.

It is a super-2 number, since 2×28218099² = 1592522222347602, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (28218199) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 427 + ... + 7524.

It is an arithmetic number, because the mean of its divisors is an integer number (1940288).

Almost surely, 2^28218099 is an apocalyptic number.

28218099 is a deficient number, since it is larger than the sum of its proper divisors (18348813).

28218099 is a wasteful number, since it uses less digits than its factorization.

28218099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7987 (or 7974 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 28218099 is about 5312.0710650367. The cubic root of 28218099 is about 304.4452839421.

It can be divided in two parts, 282 and 18099, that added together give a palindrome (18381).

The spelling of 28218099 in words is "twenty-eight million, two hundred eighteen thousand, ninety-nine".