644548 has 6 divisors (see below), whose sum is σ = 1127966. Its totient is φ = 322272.

The previous prime is 644531. The next prime is 644549. The reversal of 644548 is 845446.

644548 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 636804 + 7744 = 798^2 + 88^2 .

It is not an unprimeable number, because it can be changed into a prime (644549) by changing a digit.

644548 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 as a sum of consecutive naturals, namely, 80565 + ... + 80572.

2⁶⁴⁴⁵⁴⁸ is an apocalyptic number.

It is an amenable number.

644548 is a deficient number, since it is larger than the sum of its proper divisors (483418).

644548 is a wasteful number, since it uses less digits than its factorization.

644548 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161141 (or 161139 counting only the distinct ones).

The product of its digits is 15360, while the sum is 31.

The square root of 644548 is about 802.8374679846. The cubic root of 644548 is about 86.3810386488.

The spelling of 644548 in words is "six hundred forty-four thousand, five hundred forty-eight".