28931113 has 6 divisors (see below), whose sum is σ = 29116334. Its totient is φ = 28746816.

The previous prime is 28931099. The next prime is 28931191. The reversal of 28931113 is 31113982.

It can be written as a sum of positive squares in 3 ways, for example, as 15586704 + 13344409 = 3948^2 + 3653^2 .

It is not a de Polignac number, because 28931113 - 2⁵ = 28931081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28931213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 85681 + ... + 86017.

Almost surely, 2^28931113 is an apocalyptic number.

It is an amenable number.

28931113 is a deficient number, since it is larger than the sum of its proper divisors (185221).

28931113 is an frugal number, since it uses more digits than its factorization.

28931113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 923 (or 630 counting only the distinct ones).

The product of its digits is 1296, while the sum is 28.

The square root of 28931113 is about 5378.7650069509. The cubic root of 28931113 is about 306.9882222349.

The spelling of 28931113 in words is "twenty-eight million, nine hundred thirty-one thousand, one hundred thirteen".