28513218 has 16 divisors (see below), whose sum is σ = 57127680. Its totient is φ = 9487536.

The previous prime is 28513213. The next prime is 28513229. The reversal of 28513218 is 81231582.

It is not an unprimeable number, because it can be changed into a prime (28513213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273 + ... + 7556.

It is an arithmetic number, because the mean of its divisors is an integer number (3570480).

Almost surely, 2^28513218 is an apocalyptic number.

28513218 is an abundant number, since it is smaller than the sum of its proper divisors (28614462).

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

28513218 is a wasteful number, since it uses less digits than its factorization.

28513218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8441.

The product of its digits is 3840, while the sum is 30.

The square root of 28513218 is about 5339.7769616343. The cubic root of 28513218 is about 305.5029523011.

The spelling of 28513218 in words is "twenty-eight million, five hundred thirteen thousand, two hundred eighteen".