28287980 has 96 divisors (see below), whose sum is σ = 71909376. Its totient is φ = 9144576.

The previous prime is 28287929. The next prime is 28288019. The reversal of 28287980 is 8978282.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 222677 + ... + 222803.

It is an arithmetic number, because the mean of its divisors is an integer number (749056).

Almost surely, 2^28287980 is an apocalyptic number.

28287980 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 28287980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35954688).

28287980 is an abundant number, since it is smaller than the sum of its proper divisors (43621396).

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

28287980 is a wasteful number, since it uses less digits than its factorization.

28287980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 221 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 44.

The square root of 28287980 is about 5318.6445641723. The cubic root of 28287980 is about 304.6963923155.

The spelling of 28287980 in words is "twenty-eight million, two hundred eighty-seven thousand, nine hundred eighty".