28347280 has 80 divisors (see below), whose sum is σ = 71964144. Its totient is φ = 10321920.

The previous prime is 28347269. The next prime is 28347281. The reversal of 28347280 is 8274382.

It can be written as a sum of positive squares in 8 ways, for example, as 1140624 + 27206656 = 1068^2 + 5216^2 .

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (28347281) 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, 100740 + ... + 101020.

Almost surely, 2^28347280 is an apocalyptic number.

28347280 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 28347280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35982072).

28347280 is an abundant number, since it is smaller than the sum of its proper divisors (43616864).

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

28347280 is a wasteful number, since it uses less digits than its factorization.

28347280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404 (or 398 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 34.

The square root of 28347280 is about 5324.2163742658. The cubic root of 28347280 is about 304.9091550638.

The spelling of 28347280 in words is "twenty-eight million, three hundred forty-seven thousand, two hundred eighty".