6808863781 has 4 divisors (see below), whose sum is σ = 6809119564. Its totient is φ = 6808608000.

The previous prime is 6808863773. The next prime is 6808863829. The reversal of 6808863781 is 1873688086.

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 1116161281 + 5692702500 = 33409^2 + 75450^2 .

It is a cyclic number.

It is not a de Polignac number, because 6808863781 - 2³ = 6808863773 is a prime.

It is a super-2 number, since 2×6808863781² = 92721251976427231922, which 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 (6808863701) 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, 82620 + ... + 142981.

It is an arithmetic number, because the mean of its divisors is an integer number (1702279891).

Almost surely, 2^6808863781 is an apocalyptic number.

It is an amenable number.

6808863781 is a deficient number, since it is larger than the sum of its proper divisors (255783).

6808863781 is a wasteful number, since it uses less digits than its factorization.

6808863781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255782.

The product of its (nonzero) digits is 3096576, while the sum is 55.

The square root of 6808863781 is about 82515.8395764110. The cubic root of 6808863781 is about 1895.3592912957.

The spelling of 6808863781 in words is "six billion, eight hundred eight million, eight hundred sixty-three thousand, seven hundred eighty-one".