28539864 has 96 divisors (see below), whose sum is σ = 81965520. Its totient is φ = 9300096.

The previous prime is 28539853. The next prime is 28539877. The reversal of 28539864 is 46893582.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 102894 + ... + 103170.

Almost surely, 2^28539864 is an apocalyptic number.

28539864 is a gapful number since it is divisible by the number (24) 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 28539864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40982760).

28539864 is an abundant number, since it is smaller than the sum of its proper divisors (53425656).

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

28539864 is a wasteful number, since it uses less digits than its factorization.

28539864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 335 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 28539864 is about 5342.2714270243. The cubic root of 28539864 is about 305.5980882623.

It can be divided in two parts, 28539 and 864, that added together give a triangular number (29403 = T₂₄₂).

The spelling of 28539864 in words is "twenty-eight million, five hundred thirty-nine thousand, eight hundred sixty-four".