28871831 has 16 divisors (see below), whose sum is σ = 32695488. Its totient is φ = 25344000.

The previous prime is 28871813. The next prime is 28871833. The reversal of 28871831 is 13817882.

It is a cyclic number.

It is not a de Polignac number, because 28871831 - 2⁶ = 28871767 is a prime.

It is a super-2 number, since 2×28871831² = 1667165250585122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28871833) 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 15 ways as a sum of consecutive naturals, for example, 15131 + ... + 16931.

It is an arithmetic number, because the mean of its divisors is an integer number (2043468).

Almost surely, 2^28871831 is an apocalyptic number.

28871831 is a deficient number, since it is larger than the sum of its proper divisors (3823657).

28871831 is a wasteful number, since it uses less digits than its factorization.

28871831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882.

The product of its digits is 21504, while the sum is 38.

The square root of 28871831 is about 5373.2514365140. The cubic root of 28871831 is about 306.7783982962.

The spelling of 28871831 in words is "twenty-eight million, eight hundred seventy-one thousand, eight hundred thirty-one".