28517880 has 64 divisors (see below), whose sum is σ = 86855040. Its totient is φ = 7489152.

The previous prime is 28517851. The next prime is 28517893. The reversal of 28517880 is 8871582.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6267 + ... + 9813.

It is an arithmetic number, because the mean of its divisors is an integer number (1357110).

Almost surely, 2^28517880 is an apocalyptic number.

28517880 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 28517880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43427520).

28517880 is an abundant number, since it is smaller than the sum of its proper divisors (58337160).

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

28517880 is a wasteful number, since it uses less digits than its factorization.

28517880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3628 (or 3624 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 39.

The square root of 28517880 is about 5340.2134788789. The cubic root of 28517880 is about 305.5196016220.

It can be divided in two parts, 2851 and 7880, that added together give a triangular number (10731 = T₁₄₆).

The spelling of 28517880 in words is "twenty-eight million, five hundred seventeen thousand, eight hundred eighty".