6397999 has 2 divisors, whose sum is σ = 6398000. Its totient is φ = 6397998.

The previous prime is 6397991. The next prime is 6398017. The reversal of 6397999 is 9997936.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6397999 - 2³ = 6397991 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6397991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3198999 + 3199000.

It is an arithmetic number, because the mean of its divisors is an integer number (3199000).

Almost surely, 2^6397999 is an apocalyptic number.

6397999 is a deficient number, since it is larger than the sum of its proper divisors (1).

6397999 is an equidigital number, since it uses as much as digits as its factorization.

6397999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 826686, while the sum is 52.

The square root of 6397999 is about 2529.4266148675. The cubic root of 6397999 is about 185.6442017041.

It can be divided in two parts, 6397 and 999, that added together give a square (7396 = 86²).

The spelling of 6397999 in words is "six million, three hundred ninety-seven thousand, nine hundred ninety-nine".