643000079 has 2 divisors, whose sum is σ = 643000080. Its totient is φ = 643000078.

The previous prime is 643000067. The next prime is 643000117. The reversal of 643000079 is 970000346.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 643000079 - 2⁴ = 643000063 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643009079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321500039 + 321500040.

It is an arithmetic number, because the mean of its divisors is an integer number (321500040).

Almost surely, 2^643000079 is an apocalyptic number.

643000079 is a deficient number, since it is larger than the sum of its proper divisors (1).

643000079 is an equidigital number, since it uses as much as digits as its factorization.

643000079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 29.

The square root of 643000079 is about 25357.4462239398. The cubic root of 643000079 is about 863.1183345639.

The spelling of 643000079 in words is "six hundred forty-three million, seventy-nine", and thus it is an aban number.