645064354637 has 2 divisors, whose sum is σ = 645064354638. Its totient is φ = 645064354636.

The previous prime is 645064354609. The next prime is 645064354699. The reversal of 645064354637 is 736453460546.

645064354637 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 374894145796 + 270170208841 = 612286^2 + 519779^2 .

It is a cyclic number.

It is not a de Polignac number, because 645064354637 - 2¹⁴ = 645064338253 is a prime.

It is a super-2 number, since 2×645064354637² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645064354237) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322532177318 + 322532177319.

It is an arithmetic number, because the mean of its divisors is an integer number (322532177319).

Almost surely, 2^645064354637 is an apocalyptic number.

It is an amenable number.

645064354637 is a deficient number, since it is larger than the sum of its proper divisors (1).

645064354637 is an equidigital number, since it uses as much as digits as its factorization.

645064354637 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 21772800, while the sum is 53.

The spelling of 645064354637 in words is "six hundred forty-five billion, sixty-four million, three hundred fifty-four thousand, six hundred thirty-seven".