28218810 has 32 divisors (see below), whose sum is σ = 71710272. Its totient is φ = 7082240.

The previous prime is 28218809. The next prime is 28218811. The reversal of 28218810 is 1881282.

It is an interprime number because it is at equal distance from previous prime (28218809) and next prime (28218811).

It is a super-2 number, since 2×28218810² = 1592602475632200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (28218811) 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, 27156 + ... + 28175.

It is an arithmetic number, because the mean of its divisors is an integer number (2240946).

Almost surely, 2^28218810 is an apocalyptic number.

28218810 is an abundant number, since it is smaller than the sum of its proper divisors (43491462).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28218810 is a wasteful number, since it uses less digits than its factorization.

28218810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55358.

The product of its (nonzero) digits is 2048, while the sum is 30.

The square root of 28218810 is about 5312.1379876656. The cubic root of 28218810 is about 304.4478409154.

The spelling of 28218810 in words is "twenty-eight million, two hundred eighteen thousand, eight hundred ten".