645695117 has 2 divisors, whose sum is σ = 645695118. Its totient is φ = 645695116.

The previous prime is 645695023. The next prime is 645695137. The reversal of 645695117 is 711596546.

645695117 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 383611396 + 262083721 = 19586^2 + 16189^2 .

It is a cyclic number.

It is not a de Polignac number, because 645695117 - 2¹² = 645691021 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645695137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322847558 + 322847559.

It is an arithmetic number, because the mean of its divisors is an integer number (322847559).

Almost surely, 2^645695117 is an apocalyptic number.

It is an amenable number.

645695117 is a deficient number, since it is larger than the sum of its proper divisors (1).

645695117 is an equidigital number, since it uses as much as digits as its factorization.

645695117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 226800, while the sum is 44.

The square root of 645695117 is about 25410.5316158478. The cubic root of 645695117 is about 864.3225305655.

The spelling of 645695117 in words is "six hundred forty-five million, six hundred ninety-five thousand, one hundred seventeen".