644484 has 24 divisors (see below), whose sum is σ = 1540000. Its totient is φ = 209664.

The previous prime is 644447. The next prime is 644489. The reversal of 644484 is 484446.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a d-powerful number, because it can be written as 6⁷ + 4 + 4⁶ + 4⁸ + 8⁵ + 4⁹ .

It is not an unprimeable number, because it can be changed into a prime (644489) by changing a digit.

644484 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 7 ways as a sum of consecutive naturals, for example, 109 + ... + 1140.

2⁶⁴⁴⁴⁸⁴ is an apocalyptic number.

It is an amenable number.

644484 is an abundant number, since it is smaller than the sum of its proper divisors (895516).

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

644484 is a wasteful number, since it uses less digits than its factorization.

644484 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1299 (or 1297 counting only the distinct ones).

The product of its digits is 12288, while the sum is 30.

The square root of 644484 is about 802.7976083671. The cubic root of 644484 is about 86.3781795034.

It can be divided in two parts, 644 and 484, that added together give a triangular number (1128 = T₄₇).

The spelling of 644484 in words is "six hundred forty-four thousand, four hundred eighty-four".