644048 has 10 divisors (see below), whose sum is σ = 1247874. Its totient is φ = 322016.

The previous prime is 644047. The next prime is 644051. The reversal of 644048 is 840446.

644048 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., 620944 + 23104 = 788^2 + 152^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20111 + ... + 20142.

2⁶⁴⁴⁰⁴⁸ is an apocalyptic number.

It is an amenable number.

644048 is a deficient number, since it is larger than the sum of its proper divisors (603826).

644048 is a wasteful number, since it uses less digits than its factorization.

644048 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40261 (or 40255 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 26.

The square root of 644048 is about 802.5260120395. The cubic root of 644048 is about 86.3586965361.

The spelling of 644048 in words is "six hundred forty-four thousand, forty-eight".