645545269 has 2 divisors, whose sum is σ = 645545270. Its totient is φ = 645545268.

The previous prime is 645545207. The next prime is 645545279. The reversal of 645545269 is 962545546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 559890244 + 85655025 = 23662^2 + 9255^2 .

It is a cyclic number.

It is not a de Polignac number, because 645545269 - 2¹³ = 645537077 is a prime.

It is a super-2 number, since 2×645545269² = 833457388656564722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (645545279) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322772634 + 322772635.

It is an arithmetic number, because the mean of its divisors is an integer number (322772635).

Almost surely, 2^645545269 is an apocalyptic number.

It is an amenable number.

645545269 is a deficient number, since it is larger than the sum of its proper divisors (1).

645545269 is an equidigital number, since it uses as much as digits as its factorization.

645545269 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296000, while the sum is 46.

The square root of 645545269 is about 25407.5829035349. The cubic root of 645545269 is about 864.2556635982.

The spelling of 645545269 in words is "six hundred forty-five million, five hundred forty-five thousand, two hundred sixty-nine".