644041 has 8 divisors (see below), whose sum is σ = 670464. Its totient is φ = 618240.

The previous prime is 644029. The next prime is 644047. The reversal of 644041 is 140446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644041 - 2⁵ = 644009 is a prime.

It is a Duffinian number.

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

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 in 7 ways as a sum of consecutive naturals, for example, 3241 + ... + 3433.

It is an arithmetic number, because the mean of its divisors is an integer number (83808).

2⁶⁴⁴⁰⁴¹ is an apocalyptic number.

It is an amenable number.

644041 is a deficient number, since it is larger than the sum of its proper divisors (26423).

644041 is a wasteful number, since it uses less digits than its factorization.

644041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 644041 is about 802.5216507983. The cubic root of 644041 is about 86.3583836644.

Adding to 644041 its reverse (140446), we get a palindrome (784487).

The spelling of 644041 in words is "six hundred forty-four thousand, forty-one".