6813478243681 has 4 divisors (see below), whose sum is σ = 6942034437012. Its totient is φ = 6684922050352.

The previous prime is 6813478243613. The next prime is 6813478243697. The reversal of 6813478243681 is 1863428743186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4876217902656 + 1937260341025 = 2208216^2 + 1391855^2 .

It is a cyclic number.

It is not a de Polignac number, because 6813478243681 - 2⁷ = 6813478243553 is a prime.

It is a super-2 number, since 2×6813478243681² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6813478243981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64278096586 + ... + 64278096691.

It is an arithmetic number, because the mean of its divisors is an integer number (1735508609253).

Almost surely, 2^{6813478243681} is an apocalyptic number.

It is an amenable number.

6813478243681 is a deficient number, since it is larger than the sum of its proper divisors (128556193331).

6813478243681 is a wasteful number, since it uses less digits than its factorization.

6813478243681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128556193330.

The product of its digits is 37158912, while the sum is 61.

The spelling of 6813478243681 in words is "six trillion, eight hundred thirteen billion, four hundred seventy-eight million, two hundred forty-three thousand, six hundred eighty-one".