28223680 has 56 divisors (see below), whose sum is σ = 68031360. Its totient is φ = 11151360.

The previous prime is 28223659. The next prime is 28223687. The reversal of 28223680 is 8632282.

It is a super-2 number, since 2×28223680² = 1593152225484800, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28223687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27985 + ... + 28975.

Almost surely, 2^28223680 is an apocalyptic number.

28223680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28223680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34015680).

28223680 is an abundant number, since it is smaller than the sum of its proper divisors (39807680).

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

28223680 is an equidigital number, since it uses as much as digits as its factorization.

28223680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1097 (or 1087 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 28223680 is about 5312.5963520674. The cubic root of 28223680 is about 304.4653537694.

The spelling of 28223680 in words is "twenty-eight million, two hundred twenty-three thousand, six hundred eighty".