6391439 has 4 divisors (see below), whose sum is σ = 6767424. Its totient is φ = 6015456.

The previous prime is 6391421. The next prime is 6391453. The reversal of 6391439 is 9341936.

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

It is a cyclic number.

It is not a de Polignac number, because 6391439 - 2⁸ = 6391183 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6391399 and 6391408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6391409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 187967 + ... + 188000.

It is an arithmetic number, because the mean of its divisors is an integer number (1691856).

Almost surely, 2^6391439 is an apocalyptic number.

6391439 is a deficient number, since it is larger than the sum of its proper divisors (375985).

6391439 is a wasteful number, since it uses less digits than its factorization.

6391439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375984.

The product of its digits is 17496, while the sum is 35.

The square root of 6391439 is about 2528.1295457314. The cubic root of 6391439 is about 185.5807317337.

The spelling of 6391439 in words is "six million, three hundred ninety-one thousand, four hundred thirty-nine".