645143565 has 48 divisors (see below), whose sum is σ = 1141152768. Its totient is φ = 310992000.

The previous prime is 645143563. The next prime is 645143593. The reversal of 645143565 is 565341546.

It is not a de Polignac number, because 645143565 - 2¹ = 645143563 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645143563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 345735 + ... + 347595.

It is an arithmetic number, because the mean of its divisors is an integer number (23774016).

Almost surely, 2^645143565 is an apocalyptic number.

It is an amenable number.

645143565 is a deficient number, since it is larger than the sum of its proper divisors (496009203).

645143565 is a wasteful number, since it uses less digits than its factorization.

645143565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2082 (or 2071 counting only the distinct ones).

The product of its digits is 216000, while the sum is 39.

The square root of 645143565 is about 25399.6764743175. The cubic root of 645143565 is about 864.0763593671.

The spelling of 645143565 in words is "six hundred forty-five million, one hundred forty-three thousand, five hundred sixty-five".