28160931 has 4 divisors (see below), whose sum is σ = 37547912. Its totient is φ = 18773952.

The previous prime is 28160929. The next prime is 28160963. The reversal of 28160931 is 13906182.

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

It is not a de Polignac number, because 28160931 - 2¹ = 28160929 is a prime.

It is a super-2 number, since 2×28160931² = 1586076069573522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28160981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4693486 + ... + 4693491.

It is an arithmetic number, because the mean of its divisors is an integer number (9386978).

Almost surely, 2^28160931 is an apocalyptic number.

28160931 is a deficient number, since it is larger than the sum of its proper divisors (9386981).

28160931 is an equidigital number, since it uses as much as digits as its factorization.

28160931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9386980.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 28160931 is about 5306.6873848004. The cubic root of 28160931 is about 304.2395496163.

The spelling of 28160931 in words is "twenty-eight million, one hundred sixty thousand, nine hundred thirty-one".