644038 has 8 divisors (see below), whose sum is σ = 982080. Its totient is φ = 316680.

The previous prime is 644029. The next prime is 644047. The reversal of 644038 is 830446.

It is an interprime number because it is at equal distance from previous prime (644029) and next prime (644047).

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

It is a congruent number.

It is an unprimeable number.

644038 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 in 3 ways as a sum of consecutive naturals, for example, 2518 + ... + 2761.

It is an arithmetic number, because the mean of its divisors is an integer number (122760).

2⁶⁴⁴⁰³⁸ is an apocalyptic number.

644038 is a deficient number, since it is larger than the sum of its proper divisors (338042).

644038 is a wasteful number, since it uses less digits than its factorization.

644038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5342.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 644038 is about 802.5197816877. The cubic root of 644038 is about 86.3582495759.

It can be divided in two parts, 6 and 44038, that added together give a palindrome (44044).

The spelling of 644038 in words is "six hundred forty-four thousand, thirty-eight".