28018 has 4 divisors (see below), whose sum is σ = 42030. Its totient is φ = 14008.

The previous prime is 28001. The next prime is 28019. The reversal of 28018 is 81082.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20449 + 7569 = 143^2 + 87^2 .

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 27986 and 28004.

It is not an unprimeable number, because it can be changed into a prime (28019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7003 + ... + 7006.

2²⁸⁰¹⁸ is an apocalyptic number.

28018 is a deficient number, since it is larger than the sum of its proper divisors (14012).

28018 is a wasteful number, since it uses less digits than its factorization.

28018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14011.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 28018 is about 167.3857819529. The cubic root of 28018 is about 30.3723953013.

It can be divided in two parts, 2801 and 8, that added together give a square (2809 = 53²).

The spelling of 28018 in words is "twenty-eight thousand, eighteen".