28116505 has 4 divisors (see below), whose sum is σ = 33739812. Its totient is φ = 22493200.

The previous prime is 28116467. The next prime is 28116527. The reversal of 28116505 is 50561182.

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

It can be written as a sum of positive squares in 2 ways, for example, as 19289664 + 8826841 = 4392^2 + 2971^2 .

It is not a de Polignac number, because 28116505 - 2⁷ = 28116377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2811646 + ... + 2811655.

It is an arithmetic number, because the mean of its divisors is an integer number (8434953).

Almost surely, 2^28116505 is an apocalyptic number.

It is an amenable number.

28116505 is a deficient number, since it is larger than the sum of its proper divisors (5623307).

28116505 is an equidigital number, since it uses as much as digits as its factorization.

28116505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5623306.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 28116505 is about 5302.4998821311. The cubic root of 28116505 is about 304.0794784401.

Adding to 28116505 its reverse (50561182), we get a palindrome (78677687).

It can be divided in two parts, 2811 and 6505, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 28116505 in words is "twenty-eight million, one hundred sixteen thousand, five hundred five".