28408320 has 200 divisors, whose sum is σ = 102492324. Its totient is φ = 7520256.

The previous prime is 28408319. The next prime is 28408333. The reversal of 28408320 is 2380482.

It can be written as a sum of positive squares in 2 ways, for example, as 28387584 + 20736 = 5328^2 + 144^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 207292 + ... + 207428.

Almost surely, 2^28408320 is an apocalyptic number.

28408320 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 28408320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51246162).

28408320 is an abundant number, since it is smaller than the sum of its proper divisors (74084004).

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

28408320 is an equidigital number, since it uses as much as digits as its factorization.

28408320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 28408320 is about 5329.9455907167. The cubic root of 28408320 is about 305.1278510845.

The spelling of 28408320 in words is "twenty-eight million, four hundred eight thousand, three hundred twenty".