644852 has 12 divisors (see below), whose sum is σ = 1215396. Its totient is φ = 297600.

The previous prime is 644843. The next prime is 644857. The reversal of 644852 is 258446.

It can be written as a sum of positive squares in 2 ways, for example, as 163216 + 481636 = 404^2 + 694^2 .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644852.

It is not an unprimeable number, because it can be changed into a prime (644857) by changing a digit.

644852 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, 6149 + ... + 6252.

It is an arithmetic number, because the mean of its divisors is an integer number (101283).

2⁶⁴⁴⁸⁵² is an apocalyptic number.

It is an amenable number.

644852 is a deficient number, since it is larger than the sum of its proper divisors (570544).

644852 is a wasteful number, since it uses less digits than its factorization.

644852 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12418 (or 12416 counting only the distinct ones).

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

The square root of 644852 is about 803.0267741489. The cubic root of 644852 is about 86.3946170057.

The spelling of 644852 in words is "six hundred forty-four thousand, eight hundred fifty-two".