645064354609 has 2 divisors, whose sum is σ = 645064354610. Its totient is φ = 645064354608.

The previous prime is 645064354603. The next prime is 645064354637. The reversal of 645064354609 is 906453460546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 590192697600 + 54871657009 = 768240^2 + 234247^2 .

It is a cyclic number.

It is not a de Polignac number, because 645064354609 - 2³⁷ = 507625401137 is a prime.

It is a super-2 number, since 2×645064354609² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (645064354603) 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, 322532177304 + 322532177305.

It is an arithmetic number, because the mean of its divisors is an integer number (322532177305).

Almost surely, 2^645064354609 is an apocalyptic number.

It is an amenable number.

645064354609 is a deficient number, since it is larger than the sum of its proper divisors (1).

645064354609 is an equidigital number, since it uses as much as digits as its factorization.

645064354609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9331200, while the sum is 52.

The spelling of 645064354609 in words is "six hundred forty-five billion, sixty-four million, three hundred fifty-four thousand, six hundred nine".