8318991 has 4 divisors (see below), whose sum is σ = 11091992. Its totient is φ = 5545992.

The previous prime is 8318987. The next prime is 8318993. The reversal of 8318991 is 1998138.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 8318991 - 2² = 8318987 is a prime.

It is a super-2 number, since 2×8318991² = 138411222516162, which contains 22 as substring.

It is a Duffinian number.

8318991 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8318993) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1386496 + ... + 1386501.

It is an arithmetic number, because the mean of its divisors is an integer number (2772998).

Almost surely, 2^8318991 is an apocalyptic number.

8318991 is a deficient number, since it is larger than the sum of its proper divisors (2773001).

8318991 is a wasteful number, since it uses less digits than its factorization.

8318991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2773000.

The product of its digits is 15552, while the sum is 39.

The square root of 8318991 is about 2884.2661111624. The cubic root of 8318991 is about 202.6236891040.

The spelling of 8318991 in words is "eight million, three hundred eighteen thousand, nine hundred ninety-one".