28257880 has 64 divisors (see below), whose sum is σ = 74384640. Its totient is φ = 9459072.

The previous prime is 28257847. The next prime is 28257907. The reversal of 28257880 is 8875282.

It is a Harshad number since it is a multiple of its sum of digits (40).

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, 10867 + ... + 13213.

It is an arithmetic number, because the mean of its divisors is an integer number (1162260).

Almost surely, 2^28257880 is an apocalyptic number.

28257880 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 28257880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37192320).

28257880 is an abundant number, since it is smaller than the sum of its proper divisors (46126760).

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

28257880 is a wasteful number, since it uses less digits than its factorization.

28257880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2408 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 40.

The square root of 28257880 is about 5315.8141427255. The cubic root of 28257880 is about 304.5882826016.

The spelling of 28257880 in words is "twenty-eight million, two hundred fifty-seven thousand, eight hundred eighty".