806781 has 4 divisors (see below), whose sum is σ = 1075712. Its totient is φ = 537852.

The previous prime is 806761. The next prime is 806783. The reversal of 806781 is 187608.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 806781 - 2⁹ = 806269 is a prime.

It is a super-2 number, since 2×806781² = 1301791163922, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

806781 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 806781.

It is not an unprimeable number, because it can be changed into a prime (806783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134461 + ... + 134466.

It is an arithmetic number, because the mean of its divisors is an integer number (268928).

2⁸⁰⁶⁷⁸¹ is an apocalyptic number.

It is an amenable number.

806781 is a deficient number, since it is larger than the sum of its proper divisors (268931).

806781 is a wasteful number, since it uses less digits than its factorization.

806781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268930.

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 806781 is about 898.2098863851. The cubic root of 806781 is about 93.0933275172.

The spelling of 806781 in words is "eight hundred six thousand, seven hundred eighty-one".