28138874 has 16 divisors (see below), whose sum is σ = 44732520. Its totient is φ = 13251840.

The previous prime is 28138849. The next prime is 28138883. The reversal of 28138874 is 47883182.

It can be written as a sum of positive squares in 4 ways, for example, as 24078649 + 4060225 = 4907^2 + 2015^2 .

It is a Harshad number since it is a multiple of its sum of digits (41).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3539 + ... + 8294.

Almost surely, 2^28138874 is an apocalyptic number.

28138874 is a deficient number, since it is larger than the sum of its proper divisors (16593646).

28138874 is a wasteful number, since it uses less digits than its factorization.

28138874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11905.

The product of its digits is 86016, while the sum is 41.

The square root of 28138874 is about 5304.6087508882. The cubic root of 28138874 is about 304.1600971705.

The spelling of 28138874 in words is "twenty-eight million, one hundred thirty-eight thousand, eight hundred seventy-four".