6399917 has 2 divisors, whose sum is σ = 6399918. Its totient is φ = 6399916.

The previous prime is 6399889. The next prime is 6399929. The reversal of 6399917 is 7199936.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6056521 + 343396 = 2461^2 + 586^2 .

It is a cyclic number.

It is not a de Polignac number, because 6399917 - 2²² = 2205613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6399947) 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 as a sum of consecutive naturals, namely, 3199958 + 3199959.

It is an arithmetic number, because the mean of its divisors is an integer number (3199959).

Almost surely, 2^6399917 is an apocalyptic number.

It is an amenable number.

6399917 is a deficient number, since it is larger than the sum of its proper divisors (1).

6399917 is an equidigital number, since it uses as much as digits as its factorization.

6399917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91854, while the sum is 44.

The square root of 6399917 is about 2529.8057237662. The cubic root of 6399917 is about 185.6627507330.

The spelling of 6399917 in words is "six million, three hundred ninety-nine thousand, nine hundred seventeen".