645643626346687 has 2 divisors, whose sum is σ = 645643626346688. Its totient is φ = 645643626346686.

The previous prime is 645643626346507. The next prime is 645643626346711. The reversal of 645643626346687 is 786643626346546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 645643626346687 - 2⁴³ = 636847533324479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645643626344687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322821813173343 + 322821813173344.

It is an arithmetic number, because the mean of its divisors is an integer number (322821813173344).

Almost surely, 2^{645643626346687} is an apocalyptic number.

645643626346687 is a deficient number, since it is larger than the sum of its proper divisors (1).

645643626346687 is an equidigital number, since it uses as much as digits as its factorization.

645643626346687 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15049359360, while the sum is 76.

The spelling of 645643626346687 in words is "six hundred forty-five trillion, six hundred forty-three billion, six hundred twenty-six million, three hundred forty-six thousand, six hundred eighty-seven".