28017880 has 64 divisors (see below), whose sum is σ = 70670880. Its totient is φ = 9907200.

The previous prime is 28017863. The next prime is 28017889. The reversal of 28017880 is 8871082.

It is a Smith number, since the sum of its digits (34) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28017889) 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, 15420 + ... + 17140.

Almost surely, 2^28017880 is an apocalyptic number.

28017880 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 28017880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35335440).

28017880 is an abundant number, since it is smaller than the sum of its proper divisors (42653000).

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

28017880 is a wasteful number, since it uses less digits than its factorization.

28017880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780 (or 1776 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 34.

The square root of 28017880 is about 5293.1918536928. The cubic root of 28017880 is about 303.7235193995.

The spelling of 28017880 in words is "twenty-eight million, seventeen thousand, eight hundred eighty".