643000067 has 2 divisors, whose sum is σ = 643000068. Its totient is φ = 643000066.

The previous prime is 643000063. The next prime is 643000079. The reversal of 643000067 is 760000346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643000067 - 2² = 643000063 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (643000063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321500033 + 321500034.

It is an arithmetic number, because the mean of its divisors is an integer number (321500034).

Almost surely, 2^643000067 is an apocalyptic number.

643000067 is a deficient number, since it is larger than the sum of its proper divisors (1).

643000067 is an equidigital number, since it uses as much as digits as its factorization.

643000067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 643000067 is about 25357.4459873229. The cubic root of 643000067 is about 863.1183291945.

The spelling of 643000067 in words is "six hundred forty-three million, sixty-seven", and thus it is an aban number.