643241567 has 2 divisors, whose sum is σ = 643241568. Its totient is φ = 643241566.

The previous prime is 643241531. The next prime is 643241569. The reversal of 643241567 is 765142346.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 643241567 - 2⁶ = 643241503 is a prime.

Together with 643241569, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 643241567.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643241569) 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, 321620783 + 321620784.

It is an arithmetic number, because the mean of its divisors is an integer number (321620784).

Almost surely, 2^643241567 is an apocalyptic number.

643241567 is a deficient number, since it is larger than the sum of its proper divisors (1).

643241567 is an equidigital number, since it uses as much as digits as its factorization.

643241567 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 38.

The square root of 643241567 is about 25362.2074551881. The cubic root of 643241567 is about 863.2263732403.

The spelling of 643241567 in words is "six hundred forty-three million, two hundred forty-one thousand, five hundred sixty-seven".