645584 has 20 divisors (see below), whose sum is σ = 1263684. Its totient is φ = 319488.

The previous prime is 645583. The next prime is 645599. The reversal of 645584 is 485546.

645584 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 462400 + 183184 = 680^2 + 428^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 645584.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645581) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2384 + ... + 2640.

2⁶⁴⁵⁵⁸⁴ is an apocalyptic number.

It is an amenable number.

645584 is a deficient number, since it is larger than the sum of its proper divisors (618100).

645584 is a wasteful number, since it uses less digits than its factorization.

645584 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 416 counting only the distinct ones).

The product of its digits is 19200, while the sum is 32.

The square root of 645584 is about 803.4824204673. The cubic root of 645584 is about 86.4272947600.

The spelling of 645584 in words is "six hundred forty-five thousand, five hundred eighty-four".