645284 has 12 divisors (see below), whose sum is σ = 1134924. Its totient is φ = 321024.

The previous prime is 645257. The next prime is 645313. The reversal of 645284 is 482546.

It can be written as a sum of positive squares in 2 ways, for example, as 422500 + 222784 = 650^2 + 472^2 .

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

645284 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1184 + ... + 1640.

It is an arithmetic number, because the mean of its divisors is an integer number (94577).

2⁶⁴⁵²⁸⁴ is an apocalyptic number.

It is an amenable number.

645284 is a deficient number, since it is larger than the sum of its proper divisors (489640).

645284 is a wasteful number, since it uses less digits than its factorization.

645284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 812 counting only the distinct ones).

The product of its digits is 7680, while the sum is 29.

The square root of 645284 is about 803.2957114289. The cubic root of 645284 is about 86.4139052265.

It can be divided in two parts, 645 and 284, that added together give a palindrome (929).

The spelling of 645284 in words is "six hundred forty-five thousand, two hundred eighty-four".