3806807665781 has 16 divisors (see below), whose sum is σ = 4248273101760. Its totient is φ = 3389992093440.

The previous prime is 3806807665763. The next prime is 3806807665783. The reversal of 3806807665781 is 1875667086083.

3806807665781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3806807665781 is a prime.

It is a super-2 number, since 2×3806807665781² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3806807665783) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7233590 + ... + 7741991.

It is an arithmetic number, because the mean of its divisors is an integer number (265517068860).

Almost surely, 2^{3806807665781} is an apocalyptic number.

It is an amenable number.

3806807665781 is a deficient number, since it is larger than the sum of its proper divisors (441465435979).

3806807665781 is a wasteful number, since it uses less digits than its factorization.

3806807665781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14976404.

The product of its (nonzero) digits is 81285120, while the sum is 65.

The spelling of 3806807665781 in words is "three trillion, eight hundred six billion, eight hundred seven million, six hundred sixty-five thousand, seven hundred eighty-one".