644384 has 24 divisors (see below), whose sum is σ = 1367100. Its totient is φ = 297216.

The previous prime is 644383. The next prime is 644401. The reversal of 644384 is 483446.

It can be written as a sum of positive squares in 2 ways, for example, as 595984 + 48400 = 772^2 + 220^2 .

It is not an unprimeable number, because it can be changed into a prime (644381) 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, 359 + ... + 1190.

2⁶⁴⁴³⁸⁴ is an apocalyptic number.

It is an amenable number.

644384 is an abundant number, since it is smaller than the sum of its proper divisors (722716).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644384 is a wasteful number, since it uses less digits than its factorization.

644384 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1572 (or 1564 counting only the distinct ones).

The product of its digits is 9216, while the sum is 29.

The square root of 644384 is about 802.7353237525. The cubic root of 644384 is about 86.3737117096.

It can be divided in two parts, 64438 and 4, that multiplied together give a palindrome (257752).

The spelling of 644384 in words is "six hundred forty-four thousand, three hundred eighty-four".