6459991 has 2 divisors, whose sum is σ = 6459992. Its totient is φ = 6459990.

The previous prime is 6459979. The next prime is 6460031. The reversal of 6459991 is 1999546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6459991 - 2⁷ = 6459863 is a prime.

6459991 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6459091) 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, 3229995 + 3229996.

It is an arithmetic number, because the mean of its divisors is an integer number (3229996).

Almost surely, 2^6459991 is an apocalyptic number.

6459991 is a deficient number, since it is larger than the sum of its proper divisors (1).

6459991 is an equidigital number, since it uses as much as digits as its factorization.

6459991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 87480, while the sum is 43.

The square root of 6459991 is about 2541.6512349258. The cubic root of 6459991 is about 186.2418617227.

The spelling of 6459991 in words is "six million, four hundred fifty-nine thousand, nine hundred ninety-one".