645312771289 has 2 divisors, whose sum is σ = 645312771290. Its totient is φ = 645312771288.

The previous prime is 645312771287. The next prime is 645312771407. The reversal of 645312771289 is 982177213546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 556639842889 + 88672928400 = 746083^2 + 297780^2 .

It is a cyclic number.

It is not a de Polignac number, because 645312771289 - 2¹ = 645312771287 is a prime.

Together with 645312771287, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (645312771281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322656385644 + 322656385645.

It is an arithmetic number, because the mean of its divisors is an integer number (322656385645).

Almost surely, 2^645312771289 is an apocalyptic number.

It is an amenable number.

645312771289 is a deficient number, since it is larger than the sum of its proper divisors (1).

645312771289 is an equidigital number, since it uses as much as digits as its factorization.

645312771289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 55.

The spelling of 645312771289 in words is "six hundred forty-five billion, three hundred twelve million, seven hundred seventy-one thousand, two hundred eighty-nine".