643011334517 has 2 divisors, whose sum is σ = 643011334518. Its totient is φ = 643011334516.

The previous prime is 643011334453. The next prime is 643011334571. The reversal of 643011334517 is 715433110346.

Together with next prime (643011334571) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 564480239761 + 78531094756 = 751319^2 + 280234^2 .

It is a cyclic number.

It is not a de Polignac number, because 643011334517 - 2⁶ = 643011334453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (643013334517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321505667258 + 321505667259.

It is an arithmetic number, because the mean of its divisors is an integer number (321505667259).

Almost surely, 2^643011334517 is an apocalyptic number.

It is an amenable number.

643011334517 is a deficient number, since it is larger than the sum of its proper divisors (1).

643011334517 is an equidigital number, since it uses as much as digits as its factorization.

643011334517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 38.

The spelling of 643011334517 in words is "six hundred forty-three billion, eleven million, three hundred thirty-four thousand, five hundred seventeen".