6991312679 has 16 divisors (see below), whose sum is σ = 7974832320. Its totient is φ = 6071738880.

The previous prime is 6991312667. The next prime is 6991312687. The reversal of 6991312679 is 9762131996.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6991312679 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 6991312679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991312609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1186262 + ... + 1192140.

It is an arithmetic number, because the mean of its divisors is an integer number (498427020).

Almost surely, 2^6991312679 is an apocalyptic number.

6991312679 is a deficient number, since it is larger than the sum of its proper divisors (983519641).

6991312679 is a wasteful number, since it uses less digits than its factorization.

6991312679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11290.

The product of its digits is 1102248, while the sum is 53.

The square root of 6991312679 is about 83614.0698626732. The cubic root of 6991312679 is about 1912.1395100748.

The spelling of 6991312679 in words is "six billion, nine hundred ninety-one million, three hundred twelve thousand, six hundred seventy-nine".