6891391 has 8 divisors (see below), whose sum is σ = 7442064. Its totient is φ = 6343680.

The previous prime is 6891383. The next prime is 6891413. The reversal of 6891391 is 1931986.

6891391 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6891391 - 2³ = 6891383 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6891391.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6891491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7920 + ... + 8746.

It is an arithmetic number, because the mean of its divisors is an integer number (930258).

Almost surely, 2^6891391 is an apocalyptic number.

6891391 is a deficient number, since it is larger than the sum of its proper divisors (550673).

6891391 is a wasteful number, since it uses less digits than its factorization.

6891391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1481.

The product of its digits is 11664, while the sum is 37.

The square root of 6891391 is about 2625.1459007072. The cubic root of 6891391 is about 190.2986163020.

It can be divided in two parts, 689 and 1391, that added together give a triangular number (2080 = T₆₄).

The spelling of 6891391 in words is "six million, eight hundred ninety-one thousand, three hundred ninety-one".