6812661805 has 4 divisors (see below), whose sum is σ = 8175194172. Its totient is φ = 5450129440.

The previous prime is 6812661799. The next prime is 6812661809. The reversal of 6812661805 is 5081662186.

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 768065796 + 6044596009 = 27714^2 + 77747^2 .

It is not a de Polignac number, because 6812661805 - 2²⁷ = 6678444077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6812661809) 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, 681266176 + ... + 681266185.

It is an arithmetic number, because the mean of its divisors is an integer number (2043798543).

Almost surely, 2^6812661805 is an apocalyptic number.

It is an amenable number.

6812661805 is a deficient number, since it is larger than the sum of its proper divisors (1362532367).

6812661805 is a wasteful number, since it uses less digits than its factorization.

6812661805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1362532366.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 6812661805 is about 82538.8502767030. The cubic root of 6812661805 is about 1895.7116399521.

The spelling of 6812661805 in words is "six billion, eight hundred twelve million, six hundred sixty-one thousand, eight hundred five".