87312891 has 16 divisors (see below), whose sum is σ = 118595360. Its totient is φ = 57127680.

The previous prime is 87312871. The next prime is 87312917. The reversal of 87312891 is 19821378.

It is not a de Polignac number, because 87312891 - 2¹⁰ = 87311867 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87312811) 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, 49281 + ... + 51021.

It is an arithmetic number, because the mean of its divisors is an integer number (7412210).

Almost surely, 2^87312891 is an apocalyptic number.

87312891 is a deficient number, since it is larger than the sum of its proper divisors (31282469).

87312891 is a wasteful number, since it uses less digits than its factorization.

87312891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2046.

The product of its digits is 24192, while the sum is 39.

The square root of 87312891 is about 9344.1367177498. The cubic root of 87312891 is about 443.6353277455.

The spelling of 87312891 in words is "eighty-seven million, three hundred twelve thousand, eight hundred ninety-one".