28424 has 32 divisors (see below), whose sum is σ = 64800. Its totient is φ = 11520.

The previous prime is 28411. The next prime is 28429. The reversal of 28424 is 42482.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 28396 and 28405.

It is not an unprimeable number, because it can be changed into a prime (28429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1487 + ... + 1505.

It is an arithmetic number, because the mean of its divisors is an integer number (2025).

2²⁸⁴²⁴ 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 28424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32400).

28424 is an abundant number, since it is smaller than the sum of its proper divisors (36376).

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

28424 is a wasteful number, since it uses less digits than its factorization.

28424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53 (or 49 counting only the distinct ones).

The product of its digits is 512, while the sum is 20.

The square root of 28424 is about 168.5941873257. The cubic root of 28424 is about 30.5183979298.

The spelling of 28424 in words is "twenty-eight thousand, four hundred twenty-four".