28688 has 20 divisors (see below), whose sum is σ = 61008. Its totient is φ = 12960.

The previous prime is 28687. The next prime is 28697. The reversal of 28688 is 88682.

Added to its reverse (88682) it gives a triangular number (117370 = T₄₈₄).

28688 is nontrivially palindromic in base 15.

It is a nialpdrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28688.

It is not an unprimeable number, because it can be changed into a prime (28687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95 + ... + 257.

2²⁸⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30504).

28688 is an abundant number, since it is smaller than the sum of its proper divisors (32320).

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

28688 is a wasteful number, since it uses less digits than its factorization.

28688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 182 (or 176 counting only the distinct ones).

The product of its digits is 6144, while the sum is 32.

The square root of 28688 is about 169.3753228779. The cubic root of 28688 is about 30.6125911132.

Adding to 28688 its reverse (88682), we get a triangular number (117370 = T₄₈₄).

The spelling of 28688 in words is "twenty-eight thousand, six hundred eighty-eight".