6819773981 has 2 divisors, whose sum is σ = 6819773982. Its totient is φ = 6819773980.

The previous prime is 6819773971. The next prime is 6819774011. The reversal of 6819773981 is 1893779186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5939168356 + 880605625 = 77066^2 + 29675^2 .

It is a cyclic number.

It is not a de Polignac number, because 6819773981 - 2¹⁰ = 6819772957 is a prime.

It is a super-2 number, since 2×6819773981² = 93018634303849176722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6819773981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6819773971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3409886990 + 3409886991.

It is an arithmetic number, because the mean of its divisors is an integer number (3409886991).

Almost surely, 2^6819773981 is an apocalyptic number.

It is an amenable number.

6819773981 is a deficient number, since it is larger than the sum of its proper divisors (1).

6819773981 is an equidigital number, since it uses as much as digits as its factorization.

6819773981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4572288, while the sum is 59.

The square root of 6819773981 is about 82581.9228463469. The cubic root of 6819773981 is about 1896.3710956410.

The spelling of 6819773981 in words is "six billion, eight hundred nineteen million, seven hundred seventy-three thousand, nine hundred eighty-one".