28715856 has 80 divisors (see below), whose sum is σ = 84619584. Its totient is φ = 8312832.

The previous prime is 28715849. The next prime is 28715909. The reversal of 28715856 is 65851782.

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, 9255 + ... + 11961.

Almost surely, 2^28715856 is an apocalyptic number.

28715856 is a gapful number since it is divisible by the number (26) 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 28715856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42309792).

28715856 is an abundant number, since it is smaller than the sum of its proper divisors (55903728).

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

28715856 is a wasteful number, since it uses less digits than its factorization.

28715856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2748 (or 2742 counting only the distinct ones).

The product of its digits is 134400, while the sum is 42.

The square root of 28715856 is about 5358.7177570758. The cubic root of 28715856 is about 306.2249616625.

The spelling of 28715856 in words is "twenty-eight million, seven hundred fifteen thousand, eight hundred fifty-six".