28220320 has 48 divisors (see below), whose sum is σ = 70187040. Its totient is φ = 10692864.

The previous prime is 28220317. The next prime is 28220321. The reversal of 28220320 is 2302282.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is not an unprimeable number, because it can be changed into a prime (28220321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1602 + ... + 7681.

It is an arithmetic number, because the mean of its divisors is an integer number (1462230).

Almost surely, 2^28220320 is an apocalyptic number.

28220320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28220320 is an abundant number, since it is smaller than the sum of its proper divisors (41966720).

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

28220320 is a wasteful number, since it uses less digits than its factorization.

28220320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9317 (or 9309 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 28220320 is about 5312.2801130964. The cubic root of 28220320 is about 304.4532711944.

It can be divided in two parts, 282 and 20320, that added together give a palindrome (20602).

The spelling of 28220320 in words is "twenty-eight million, two hundred twenty thousand, three hundred twenty".