6399947 has 2 divisors, whose sum is σ = 6399948. Its totient is φ = 6399946.

The previous prime is 6399931. The next prime is 6399961. The reversal of 6399947 is 7499936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6399947 - 2⁴ = 6399931 is a prime.

It is a Chen prime.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (6399917) 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, 3199973 + 3199974.

It is an arithmetic number, because the mean of its divisors is an integer number (3199974).

Almost surely, 2^6399947 is an apocalyptic number.

6399947 is a deficient number, since it is larger than the sum of its proper divisors (1).

6399947 is an equidigital number, since it uses as much as digits as its factorization.

6399947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 47.

The square root of 6399947 is about 2529.8116530683. The cubic root of 6399947 is about 185.6630408343.

It can be divided in two parts, 63999 and 47, that added together give a palindrome (64046).

The spelling of 6399947 in words is "six million, three hundred ninety-nine thousand, nine hundred forty-seven".