28707831 has 16 divisors (see below), whose sum is σ = 43569120. Its totient is φ = 18671040.

The previous prime is 28707827. The next prime is 28707857. The reversal of 28707831 is 13870782.

It is not a de Polignac number, because 28707831 - 2² = 28707827 is a prime.

It is a super-2 number, since 2×28707831² = 1648279121449122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28707871) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11860 + ... + 14073.

It is an arithmetic number, because the mean of its divisors is an integer number (2723070).

Almost surely, 2^28707831 is an apocalyptic number.

28707831 is a deficient number, since it is larger than the sum of its proper divisors (14861289).

28707831 is a wasteful number, since it uses less digits than its factorization.

28707831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25983 (or 25977 counting only the distinct ones).

The product of its (nonzero) digits is 18816, while the sum is 36.

The square root of 28707831 is about 5357.9689248819. The cubic root of 28707831 is about 306.1964328911.

It can be divided in two parts, 2870 and 7831, that added together give a palindrome (10701).

The spelling of 28707831 in words is "twenty-eight million, seven hundred seven thousand, eight hundred thirty-one".