28890 has 32 divisors (see below), whose sum is σ = 77760. Its totient is φ = 7632.

The previous prime is 28879. The next prime is 28901. The reversal of 28890 is 9882.

28890 = 74² + 75² + ... + 78².

28890 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (28879) and next prime (28901).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a nialpdrome in base 15.

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, 217 + ... + 323.

It is an arithmetic number, because the mean of its divisors is an integer number (2430).

2²⁸⁸⁹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38880).

28890 is an abundant number, since it is smaller than the sum of its proper divisors (48870).

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

28890 is a wasteful number, since it uses less digits than its factorization.

28890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 123 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 27.

The square root of 28890 is about 169.9705856906. The cubic root of 28890 is about 30.6842736531.

It can be divided in two parts, 288 and 90, that added together give a triangular number (378 = T₂₇).

The spelling of 28890 in words is "twenty-eight thousand, eight hundred ninety".