6781165813 has 2 divisors, whose sum is σ = 6781165814. Its totient is φ = 6781165812.

The previous prime is 6781165777. The next prime is 6781165837. The reversal of 6781165813 is 3185611876.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6018190929 + 762974884 = 77577^2 + 27622^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6781165813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6781165883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3390582906 + 3390582907.

It is an arithmetic number, because the mean of its divisors is an integer number (3390582907).

Almost surely, 2^6781165813 is an apocalyptic number.

It is an amenable number.

6781165813 is a deficient number, since it is larger than the sum of its proper divisors (1).

6781165813 is an equidigital number, since it uses as much as digits as its factorization.

6781165813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 46.

The square root of 6781165813 is about 82347.8342945338. The cubic root of 6781165813 is about 1892.7857367110.

It can be divided in two parts, 678116 and 5813, that added together give a square (683929 = 827²).

The spelling of 6781165813 in words is "six billion, seven hundred eighty-one million, one hundred sixty-five thousand, eight hundred thirteen".