643144079 has 2 divisors, whose sum is σ = 643144080. Its totient is φ = 643144078.

The previous prime is 643144043. The next prime is 643144097. The reversal of 643144079 is 970441346.

Together with next prime (643144097) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643144079 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643144979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321572039 + 321572040.

It is an arithmetic number, because the mean of its divisors is an integer number (321572040).

Almost surely, 2^643144079 is an apocalyptic number.

643144079 is a deficient number, since it is larger than the sum of its proper divisors (1).

643144079 is an equidigital number, since it uses as much as digits as its factorization.

643144079 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 643144079 is about 25360.2854676362. The cubic root of 643144079 is about 863.1827615975.

The spelling of 643144079 in words is "six hundred forty-three million, one hundred forty-four thousand, seventy-nine".