28172 has 6 divisors (see below), whose sum is σ = 49308. Its totient is φ = 14084.

The previous prime is 28163. The next prime is 28181. The reversal of 28172 is 27182.

It is an interprime number because it is at equal distance from previous prime (28163) and next prime (28181).

It is a super-3 number, since 3×28172³ = 67077102433344, which contains 333 as substring.

It is an Ulam number.

It is a nialpdrome in base 13 and base 15.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 3518 + ... + 3525.

It is an arithmetic number, because the mean of its divisors is an integer number (8218).

2²⁸¹⁷² is an apocalyptic number.

It is an amenable number.

28172 is a deficient number, since it is larger than the sum of its proper divisors (21136).

28172 is a wasteful number, since it uses less digits than its factorization.

28172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7047 (or 7045 counting only the distinct ones).

The product of its digits is 224, while the sum is 20.

The square root of 28172 is about 167.8451667460. The cubic root of 28172 is about 30.4279406093.

Subtracting from 28172 its reverse (27182), we obtain a triangular number (990 = T₄₄).

It can be divided in two parts, 281 and 72, that added together give a palindrome (353).

The spelling of 28172 in words is "twenty-eight thousand, one hundred seventy-two".