6999 has 4 divisors (see below), whose sum is σ = 9336.
Its totient is φ = 4664.
The previous prime is 6997. The next prime is 7001. The reversal of 6999 is 9996.
It is a semiprime because it is the product of two primes.
It is an interprime number because it is at equal distance from previous prime (6997) and next prime (7001).
It is a cyclic number.
It is not a de Polignac number, because 6999 - 21 = 6997 is a prime.
It is a D-number.
6999 is a modest number, since divided by 99 gives 69 as remainder.
6999 is a lucky number.
It is a plaindrome in base 10 and base 14.
It is a congruent number.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 6999.
It is not an unprimeable number, because it can be changed into a prime (6991) 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, 1164 + ... + 1169.
It is an arithmetic number, because the mean of its divisors is an integer number (2334).
6999 is a deficient number, since it is larger than the sum of its proper divisors (2337).
6999 is a wasteful number, since it uses less digits than its factorization.
6999 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2336.
The product of its digits is 4374, while the sum is 33.
The square root of 6999 is about 83.6600262969.
The cubic root of 6999 is about 19.1284008647.
The spelling of 6999 in words is "six thousand, nine hundred ninety-nine".