6771991 has 4 divisors (see below), whose sum is σ = 6864832. Its totient is φ = 6679152.

The previous prime is 6771979. The next prime is 6772013. The reversal of 6771991 is 1991776.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6771991 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6771911) 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, 46311 + ... + 46456.

It is an arithmetic number, because the mean of its divisors is an integer number (1716208).

Almost surely, 2^6771991 is an apocalyptic number.

6771991 is a deficient number, since it is larger than the sum of its proper divisors (92841).

6771991 is an equidigital number, since it uses as much as digits as its factorization.

6771991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92840.

The product of its digits is 23814, while the sum is 40.

The square root of 6771991 is about 2602.3049398562. The cubic root of 6771991 is about 189.1931714777.

The spelling of 6771991 in words is "six million, seven hundred seventy-one thousand, nine hundred ninety-one".