8115991 has 8 divisors (see below), whose sum is σ = 8954064. Its totient is φ = 7308480.

The previous prime is 8115977. The next prime is 8115997. The reversal of 8115991 is 1995118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 8115991 - 2⁵ = 8115959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8115997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7081 + ... + 8146.

It is an arithmetic number, because the mean of its divisors is an integer number (1119258).

Almost surely, 2^8115991 is an apocalyptic number.

8115991 is a deficient number, since it is larger than the sum of its proper divisors (838073).

8115991 is a wasteful number, since it uses less digits than its factorization.

8115991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15281.

The product of its digits is 3240, while the sum is 34.

The square root of 8115991 is about 2848.8578413111. The cubic root of 8115991 is about 200.9619574381.

The spelling of 8115991 in words is "eight million, one hundred fifteen thousand, nine hundred ninety-one".