643431505134361 has 2 divisors, whose sum is σ = 643431505134362. Its totient is φ = 643431505134360.

The previous prime is 643431505134269. The next prime is 643431505134491. The reversal of 643431505134361 is 163431505134346.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 442023040630336 + 201408464504025 = 21024344^2 + 14191845^2 .

It is a cyclic number.

It is not a de Polignac number, because 643431505134361 - 2¹³ = 643431505126169 is a prime.

It is not a weakly prime, because it can be changed into another prime (643431505138361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321715752567180 + 321715752567181.

It is an arithmetic number, because the mean of its divisors is an integer number (321715752567181).

Almost surely, 2^{643431505134361} is an apocalyptic number.

It is an amenable number.

643431505134361 is a deficient number, since it is larger than the sum of its proper divisors (1).

643431505134361 is an equidigital number, since it uses as much as digits as its factorization.

643431505134361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4665600, while the sum is 49.

The spelling of 643431505134361 in words is "six hundred forty-three trillion, four hundred thirty-one billion, five hundred five million, one hundred thirty-four thousand, three hundred sixty-one".