645585547 has 2 divisors, whose sum is σ = 645585548. Its totient is φ = 645585546.

The previous prime is 645585533. The next prime is 645585581. The reversal of 645585547 is 745585546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645585547 - 2⁷ = 645585419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 645585547.

It is not a weakly prime, because it can be changed into another prime (645585587) 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, 322792773 + 322792774.

It is an arithmetic number, because the mean of its divisors is an integer number (322792774).

Almost surely, 2^645585547 is an apocalyptic number.

645585547 is a deficient number, since it is larger than the sum of its proper divisors (1).

645585547 is an equidigital number, since it uses as much as digits as its factorization.

645585547 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360000, while the sum is 49.

The square root of 645585547 is about 25408.3755285536. The cubic root of 645585547 is about 864.2736379460.

Subtracting 645585547 from its reverse (745585546), we obtain a palindrome (99999999).

The spelling of 645585547 in words is "six hundred forty-five million, five hundred eighty-five thousand, five hundred forty-seven".