643504319 has 2 divisors, whose sum is σ = 643504320. Its totient is φ = 643504318.

The previous prime is 643504297. The next prime is 643504321. The reversal of 643504319 is 913405346.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643504319 - 2¹² = 643500223 is a prime.

It is a super-2 number, since 2×643504319² = 828195617143307522, which contains 22 as substring.

Together with 643504321, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p_33473159 and since 643504319 and 33473159 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643504819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321752159 + 321752160.

It is an arithmetic number, because the mean of its divisors is an integer number (321752160).

Almost surely, 2^643504319 is an apocalyptic number.

643504319 is a deficient number, since it is larger than the sum of its proper divisors (1).

643504319 is an equidigital number, since it uses as much as digits as its factorization.

643504319 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 643504319 is about 25367.3869170634. The cubic root of 643504319 is about 863.3438944493.

The spelling of 643504319 in words is "six hundred forty-three million, five hundred four thousand, three hundred nineteen".