8106781 has 4 divisors (see below), whose sum is σ = 8115292. Its totient is φ = 8098272.

The previous prime is 8106767. The next prime is 8106797. The reversal of 8106781 is 1876018.

8106781 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7474756 + 632025 = 2734^2 + 795^2 .

It is a cyclic number.

It is not a de Polignac number, because 8106781 - 2¹⁵ = 8074013 is a prime.

It is a super-2 number, since 2×8106781² = 131439796363922, which contains 22 as substring.

It is a Duffinian number.

8106781 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8106751) 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, 2616 + ... + 4801.

It is an arithmetic number, because the mean of its divisors is an integer number (2028823).

Almost surely, 2^8106781 is an apocalyptic number.

It is an amenable number.

8106781 is a deficient number, since it is larger than the sum of its proper divisors (8511).

8106781 is a wasteful number, since it uses less digits than its factorization.

8106781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8510.

The product of its (nonzero) digits is 2688, while the sum is 31.

The square root of 8106781 is about 2847.2409451959. The cubic root of 8106781 is about 200.8859116750.

The spelling of 8106781 in words is "eight million, one hundred six thousand, seven hundred eighty-one".