6399929 has 2 divisors, whose sum is σ = 6399930. Its totient is φ = 6399928.

The previous prime is 6399917. The next prime is 6399931. The reversal of 6399929 is 9299936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4080400 + 2319529 = 2020^2 + 1523^2 .

It is a cyclic number.

It is not a de Polignac number, because 6399929 - 2¹² = 6395833 is a prime.

Together with 6399931, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6399629) 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, 3199964 + 3199965.

It is an arithmetic number, because the mean of its divisors is an integer number (3199965).

Almost surely, 2^6399929 is an apocalyptic number.

It is an amenable number.

6399929 is a deficient number, since it is larger than the sum of its proper divisors (1).

6399929 is an equidigital number, since it uses as much as digits as its factorization.

6399929 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 236196, while the sum is 47.

The square root of 6399929 is about 2529.8080954887. The cubic root of 6399929 is about 185.6628667736.

The spelling of 6399929 in words is "six million, three hundred ninety-nine thousand, nine hundred twenty-nine".