644060 has 12 divisors (see below), whose sum is σ = 1352568. Its totient is φ = 257616.

The previous prime is 644057. The next prime is 644089. The reversal of 644060 is 60446.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 32203 = 644060 / (6 + 4 + 4 + 0 + 6 + 0).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 644060.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16082 + ... + 16121.

It is an arithmetic number, because the mean of its divisors is an integer number (112714).

2⁶⁴⁴⁰⁶⁰ is an apocalyptic number.

It is an amenable number.

644060 is an abundant number, since it is smaller than the sum of its proper divisors (708508).

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

644060 is a wasteful number, since it uses less digits than its factorization.

644060 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32212 (or 32210 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 644060 is about 802.5334883978. The cubic root of 644060 is about 86.3592328822.

The spelling of 644060 in words is "six hundred forty-four thousand, sixty".