644284 has 6 divisors (see below), whose sum is σ = 1127504. Its totient is φ = 322140.

The previous prime is 644261. The next prime is 644291. The reversal of 644284 is 482446.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80532 + ... + 80539.

2⁶⁴⁴²⁸⁴ is an apocalyptic number.

It is an amenable number.

644284 is a deficient number, since it is larger than the sum of its proper divisors (483220).

644284 is a wasteful number, since it uses less digits than its factorization.

644284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161075 (or 161073 counting only the distinct ones).

The product of its digits is 6144, while the sum is 28.

The square root of 644284 is about 802.6730343048. The cubic root of 644284 is about 86.3692434536.

The spelling of 644284 in words is "six hundred forty-four thousand, two hundred eighty-four".