6821291138 has 16 divisors (see below), whose sum is σ = 10459566720. Its totient is φ = 3334906896.

The previous prime is 6821291129. The next prime is 6821291167. The reversal of 6821291138 is 8311921286.

It is a junction number, because it is equal to n+sod(n) for n = 6821291095 and 6821291104.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 66545 + ... + 134427.

It is an arithmetic number, because the mean of its divisors is an integer number (653722920).

Almost surely, 2^6821291138 is an apocalyptic number.

6821291138 is a deficient number, since it is larger than the sum of its proper divisors (3638275582).

6821291138 is a wasteful number, since it uses less digits than its factorization.

6821291138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69001.

The product of its digits is 41472, while the sum is 41.

The square root of 6821291138 is about 82591.1081049286. The cubic root of 6821291138 is about 1896.5117102404.

The spelling of 6821291138 in words is "six billion, eight hundred twenty-one million, two hundred ninety-one thousand, one hundred thirty-eight".