6391243 has 2 divisors, whose sum is σ = 6391244. Its totient is φ = 6391242.

The previous prime is 6391241. The next prime is 6391247. The reversal of 6391243 is 3421936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6391243 - 2¹ = 6391241 is a prime.

Together with 6391241, it forms a pair of twin primes.

It is equal to p₄₃₇₈₄₂ and since 6391243 and 437842 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (6391241) 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 as a sum of consecutive naturals, namely, 3195621 + 3195622.

It is an arithmetic number, because the mean of its divisors is an integer number (3195622).

Almost surely, 2^6391243 is an apocalyptic number.

6391243 is a deficient number, since it is larger than the sum of its proper divisors (1).

6391243 is an equidigital number, since it uses as much as digits as its factorization.

6391243 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 28.

The square root of 6391243 is about 2528.0907815978. The cubic root of 6391243 is about 185.5788347068.

The spelling of 6391243 in words is "six million, three hundred ninety-one thousand, two hundred forty-three".