28287181 has 16 divisors (see below), whose sum is σ = 32538240. Its totient is φ = 24373440.

The previous prime is 28287179. The next prime is 28287187. The reversal of 28287181 is 18178282.

It is not a de Polignac number, because 28287181 - 2¹ = 28287179 is a prime.

It is a super-2 number, since 2×28287181² = 1600329217853522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28287181.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28287187) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16731 + ... + 18343.

It is an arithmetic number, because the mean of its divisors is an integer number (2033640).

Almost surely, 2^28287181 is an apocalyptic number.

It is an amenable number.

28287181 is a deficient number, since it is larger than the sum of its proper divisors (4251059).

28287181 is a wasteful number, since it uses less digits than its factorization.

28287181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716.

The product of its digits is 14336, while the sum is 37.

The square root of 28287181 is about 5318.5694505196. The cubic root of 28287181 is about 304.6935235504.

The spelling of 28287181 in words is "twenty-eight million, two hundred eighty-seven thousand, one hundred eighty-one".