28170018 has 42 divisors (see below), whose sum is σ = 63812619. Its totient is φ = 9322452.

The previous prime is 28170007. The next prime is 28170053. The reversal of 28170018 is 81007182.

It can be written as a sum of positive squares in only one way, i.e., 14085009 + 14085009 = 3753^2 + 3753^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3753.

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

It is a junction number, because it is equal to n+sod(n) for n = 28169973 and 28170000.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 202593 + ... + 202731.

Almost surely, 2^28170018 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28170018

28170018 is an abundant number, since it is smaller than the sum of its proper divisors (35642601).

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

28170018 is an frugal number, since it uses more digits than its factorization.

28170018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 27.

The square root of 28170018 is about 5307.5434995862. The cubic root of 28170018 is about 304.2722702140.

The spelling of 28170018 in words is "twenty-eight million, one hundred seventy thousand, eighteen".