6991138 has 24 divisors (see below), whose sum is σ = 13176576. Its totient is φ = 2723160.

The previous prime is 6991133. The next prime is 6991147. The reversal of 6991138 is 8311996.

It is a junction number, because it is equal to n+sod(n) for n = 6991097 and 6991106.

It is not an unprimeable number, because it can be changed into a prime (6991133) 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, 370 + ... + 3757.

It is an arithmetic number, because the mean of its divisors is an integer number (549024).

Almost surely, 2^6991138 is an apocalyptic number.

6991138 is a deficient number, since it is larger than the sum of its proper divisors (6185438).

6991138 is a wasteful number, since it uses less digits than its factorization.

6991138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4158 (or 4147 counting only the distinct ones).

The product of its digits is 11664, while the sum is 37.

The square root of 6991138 is about 2644.0760200872. The cubic root of 6991138 is about 191.2123584911.

The spelling of 6991138 in words is "six million, nine hundred ninety-one thousand, one hundred thirty-eight".