28100 has 18 divisors (see below), whose sum is σ = 61194. Its totient is φ = 11200.

The previous prime is 28099. The next prime is 28109. The reversal of 28100 is 182.

It can be written as a sum of positive squares in 3 ways, for example, as 3136 + 24964 = 56^2 + 158^2 .

It is a super-2 number, since 2×28100² = 1579220000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28109) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 41 + ... + 240.

2²⁸¹⁰⁰ is an apocalyptic number.

28100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28100 is an abundant number, since it is smaller than the sum of its proper divisors (33094).

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

28100 is a wasteful number, since it uses less digits than its factorization.

28100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 28100 is about 167.6305461424. The cubic root of 28100 is about 30.4019966371.

Adding to 28100 its reverse (182), we get a palindrome (28282).

It can be divided in two parts, 28 and 100, that added together give a 7-th power (128 = 2⁷).

The spelling of 28100 in words is "twenty-eight thousand, one hundred".