645252387397 has 2 divisors, whose sum is σ = 645252387398. Its totient is φ = 645252387396.

The previous prime is 645252387361. The next prime is 645252387463. The reversal of 645252387397 is 793783252546.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 526264644481 + 118987742916 = 725441^2 + 344946^2 .

It is a cyclic number.

It is not a de Polignac number, because 645252387397 - 2¹⁵ = 645252354629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645252387347) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322626193698 + 322626193699.

It is an arithmetic number, because the mean of its divisors is an integer number (322626193699).

Almost surely, 2^645252387397 is an apocalyptic number.

It is an amenable number.

645252387397 is a deficient number, since it is larger than the sum of its proper divisors (1).

645252387397 is an equidigital number, since it uses as much as digits as its factorization.

645252387397 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76204800, while the sum is 61.

The spelling of 645252387397 in words is "six hundred forty-five billion, two hundred fifty-two million, three hundred eighty-seven thousand, three hundred ninety-seven".