28311831 has 12 divisors (see below), whose sum is σ = 40956552. Its totient is φ = 18846096.

The previous prime is 28311823. The next prime is 28311841. The reversal of 28311831 is 13811382.

It is not a de Polignac number, because 28311831 - 2³ = 28311823 is a prime.

It is a super-2 number, since 2×28311831² = 1603119549145122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28311795 and 28311804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28311821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5200 + ... + 9146.

It is an arithmetic number, because the mean of its divisors is an integer number (3413046).

Almost surely, 2^28311831 is an apocalyptic number.

28311831 is a deficient number, since it is larger than the sum of its proper divisors (12644721).

28311831 is a wasteful number, since it uses less digits than its factorization.

28311831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4750 (or 4747 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 28311831 is about 5320.8862983529. The cubic root of 28311831 is about 304.7820031431.

The spelling of 28311831 in words is "twenty-eight million, three hundred eleven thousand, eight hundred thirty-one".