6691979 has 12 divisors (see below), whose sum is σ = 7976808. Its totient is φ = 5594400.

The previous prime is 6691969. The next prime is 6691981. The reversal of 6691979 is 9791966.

It is a happy number.

It is not a de Polignac number, because 6691979 - 2⁸ = 6691723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (6691969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 344 + ... + 3674.

It is an arithmetic number, because the mean of its divisors is an integer number (664734).

Almost surely, 2^6691979 is an apocalyptic number.

6691979 is a deficient number, since it is larger than the sum of its proper divisors (1284829).

6691979 is a wasteful number, since it uses less digits than its factorization.

6691979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3386 (or 3379 counting only the distinct ones).

The product of its digits is 183708, while the sum is 47.

The square root of 6691979 is about 2586.8859657898. The cubic root of 6691979 is about 188.4451031193.

The spelling of 6691979 in words is "six million, six hundred ninety-one thousand, nine hundred seventy-nine".