6839905637781 has 6 divisors (see below), whose sum is σ = 9879863699030. Its totient is φ = 4559937091848.

The previous prime is 6839905637779. The next prime is 6839905637791. The reversal of 6839905637781 is 1877365099386.

6839905637781 is a `hidden beast` number, since 68 + 39 + 90 + 5 + 6 + 377 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 4819715298225 + 2020190339556 = 2195385^2 + 1421334^2 .

It is not a de Polignac number, because 6839905637781 - 2¹ = 6839905637779 is a prime.

It is a super-2 number, since 2×6839905637781² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6839905637791) 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 5 ways as a sum of consecutive naturals, for example, 379994757646 + ... + 379994757663.

Almost surely, 2^{6839905637781} is an apocalyptic number.

It is an amenable number.

6839905637781 is a deficient number, since it is larger than the sum of its proper divisors (3039958061249).

6839905637781 is a wasteful number, since it uses less digits than its factorization.

6839905637781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 759989515315 (or 759989515312 counting only the distinct ones).

The product of its (nonzero) digits is 411505920, while the sum is 72.

The spelling of 6839905637781 in words is "six trillion, eight hundred thirty-nine billion, nine hundred five million, six hundred thirty-seven thousand, seven hundred eighty-one".