6991311 has 8 divisors (see below), whose sum is σ = 9353344. Its totient is φ = 4645080.

The previous prime is 6991289. The next prime is 6991319. The reversal of 6991311 is 1131996.

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

It is not a de Polignac number, because 6991311 - 2⁹ = 6990799 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 (6991319) 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, 2875 + ... + 4716.

It is an arithmetic number, because the mean of its divisors is an integer number (1169168).

Almost surely, 2^6991311 is an apocalyptic number.

6991311 is a deficient number, since it is larger than the sum of its proper divisors (2362033).

6991311 is a wasteful number, since it uses less digits than its factorization.

6991311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7901.

The product of its digits is 1458, while the sum is 30.

The square root of 6991311 is about 2644.1087345266. The cubic root of 6991311 is about 191.2139357005.

The spelling of 6991311 in words is "six million, nine hundred ninety-one thousand, three hundred eleven".