645751343157539 has 2 divisors, whose sum is σ = 645751343157540. Its totient is φ = 645751343157538.

The previous prime is 645751343157533. The next prime is 645751343157559. The reversal of 645751343157539 is 935751343157546.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645751343157539 - 2⁴⁴ = 628159157113123 is a prime.

It is not a weakly prime, because it can be changed into another prime (645751343157533) 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, 322875671578769 + 322875671578770.

It is an arithmetic number, because the mean of its divisors is an integer number (322875671578770).

Almost surely, 2^{645751343157539} is an apocalyptic number.

645751343157539 is a deficient number, since it is larger than the sum of its proper divisors (1).

645751343157539 is an equidigital number, since it uses as much as digits as its factorization.

645751343157539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 714420000, while the sum is 68.

The spelling of 645751343157539 in words is "six hundred forty-five trillion, seven hundred fifty-one billion, three hundred forty-three million, one hundred fifty-seven thousand, five hundred thirty-nine".