645596557 has 2 divisors, whose sum is σ = 645596558. Its totient is φ = 645596556.

The previous prime is 645596543. The next prime is 645596561. The reversal of 645596557 is 755695546.

645596557 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., 644855236 + 741321 = 25394^2 + 861^2 .

It is a cyclic number.

It is not a de Polignac number, because 645596557 - 2⁷ = 645596429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645546557) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322798278 + 322798279.

It is an arithmetic number, because the mean of its divisors is an integer number (322798279).

Almost surely, 2^645596557 is an apocalyptic number.

It is an amenable number.

645596557 is a deficient number, since it is larger than the sum of its proper divisors (1).

645596557 is an equidigital number, since it uses as much as digits as its factorization.

645596557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5670000, while the sum is 52.

The square root of 645596557 is about 25408.5921884704. The cubic root of 645596557 is about 864.2785511078.

The spelling of 645596557 in words is "six hundred forty-five million, five hundred ninety-six thousand, five hundred fifty-seven".