6403943999 has 2 divisors, whose sum is σ = 6403944000. Its totient is φ = 6403943998.

The previous prime is 6403943929. The next prime is 6403944017. The reversal of 6403943999 is 9993493046.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6403943999 - 2⁸ = 6403943743 is a prime.

It is a super-2 number, since 2×6403943999² = 82020997484656224002, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6403943929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3201971999 + 3201972000.

It is an arithmetic number, because the mean of its divisors is an integer number (3201972000).

Almost surely, 2^6403943999 is an apocalyptic number.

6403943999 is a deficient number, since it is larger than the sum of its proper divisors (1).

6403943999 is an equidigital number, since it uses as much as digits as its factorization.

6403943999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5668704, while the sum is 56.

The square root of 6403943999 is about 80024.6461972810. The cubic root of 6403943999 is about 1857.0168389152.

The spelling of 6403943999 in words is "six billion, four hundred three million, nine hundred forty-three thousand, nine hundred ninety-nine".