645289569 has 24 divisors (see below), whose sum is σ = 941959200. Its totient is φ = 425658240.

The previous prime is 645289543. The next prime is 645289573. The reversal of 645289569 is 965982546.

It is a happy number.

645289569 is a `hidden beast` number, since 64 + 528 + 9 + 56 + 9 = 666.

645289569 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 645289569 - 2⁷ = 645289441 is a prime.

It is a super-2 number, since 2×645289569² = 832797255720411522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (645281569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 473449 + ... + 474809.

It is an arithmetic number, because the mean of its divisors is an integer number (39248300).

Almost surely, 2^645289569 is an apocalyptic number.

It is an amenable number.

645289569 is a deficient number, since it is larger than the sum of its proper divisors (296669631).

645289569 is a wasteful number, since it uses less digits than its factorization.

645289569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1885 (or 1882 counting only the distinct ones).

The product of its digits is 4665600, while the sum is 54.

The square root of 645289569 is about 25402.5504428197. The cubic root of 645289569 is about 864.1415381871.

The spelling of 645289569 in words is "six hundred forty-five million, two hundred eighty-nine thousand, five hundred sixty-nine".