6871781 has 4 divisors (see below), whose sum is σ = 7853472. Its totient is φ = 5890092.

The previous prime is 6871769. The next prime is 6871793. The reversal of 6871781 is 1871786.

6871781 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 Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (6871769) and next prime (6871793).

It is a cyclic number.

It is not a de Polignac number, because 6871781 - 2⁶ = 6871717 is a prime.

It is a super-2 number, since 2×6871781² = 94442748223922, 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 (6871481) 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, 490835 + ... + 490848.

It is an arithmetic number, because the mean of its divisors is an integer number (1963368).

Almost surely, 2^6871781 is an apocalyptic number.

It is an amenable number.

6871781 is a deficient number, since it is larger than the sum of its proper divisors (981691).

6871781 is an equidigital number, since it uses as much as digits as its factorization.

6871781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981690.

The product of its digits is 18816, while the sum is 38.

The square root of 6871781 is about 2621.4082093409. The cubic root of 6871781 is about 190.1179415470.

The spelling of 6871781 in words is "six million, eight hundred seventy-one thousand, seven hundred eighty-one".