28120 has 32 divisors (see below), whose sum is σ = 68400. Its totient is φ = 10368.

The previous prime is 28111. The next prime is 28123. The reversal of 28120 is 2182.

28120 = T₁₉ + T₂₀ + ... + T₅₅.

It is an Ulam number.

It is a nialpdrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 28120.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28123) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 742 + ... + 778.

2²⁸¹²⁰ is an apocalyptic number.

28120 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 28120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34200).

28120 is an abundant number, since it is smaller than the sum of its proper divisors (40280).

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

28120 is a wasteful number, since it uses less digits than its factorization.

28120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67 (or 63 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 28120 is about 167.6901905300. The cubic root of 28120 is about 30.4092077371.

The spelling of 28120 in words is "twenty-eight thousand, one hundred twenty".