8515891 has 2 divisors, whose sum is σ = 8515892. Its totient is φ = 8515890.

The previous prime is 8515889. The next prime is 8515907. The reversal of 8515891 is 1985158.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8515891 - 2¹ = 8515889 is a prime.

Together with 8515889, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8515891.

It is not a weakly prime, because it can be changed into another prime (8515391) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4257945 + 4257946.

It is an arithmetic number, because the mean of its divisors is an integer number (4257946).

Almost surely, 2^8515891 is an apocalyptic number.

8515891 is a deficient number, since it is larger than the sum of its proper divisors (1).

8515891 is an equidigital number, since it uses as much as digits as its factorization.

8515891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14400, while the sum is 37.

The square root of 8515891 is about 2918.1999588788. The cubic root of 8515891 is about 204.2098554938.

The spelling of 8515891 in words is "eight million, five hundred fifteen thousand, eight hundred ninety-one".