6856381369 has 2 divisors, whose sum is σ = 6856381370. Its totient is φ = 6856381368.

The previous prime is 6856381339. The next prime is 6856381379. The reversal of 6856381369 is 9631836586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5831613225 + 1024768144 = 76365^2 + 32012^2 .

It is a cyclic number.

It is not a de Polignac number, because 6856381369 - 2¹⁵ = 6856348601 is a prime.

It is a super-2 number, since 2×6856381369² = 94019930954340628322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6856381319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3428190684 + 3428190685.

It is an arithmetic number, because the mean of its divisors is an integer number (3428190685).

Almost surely, 2^6856381369 is an apocalyptic number.

It is an amenable number.

6856381369 is a deficient number, since it is larger than the sum of its proper divisors (1).

6856381369 is an equidigital number, since it uses as much as digits as its factorization.

6856381369 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5598720, while the sum is 55.

The square root of 6856381369 is about 82803.2690719394. The cubic root of 6856381369 is about 1899.7581750399.

The spelling of 6856381369 in words is "six billion, eight hundred fifty-six million, three hundred eighty-one thousand, three hundred sixty-nine".