644141 has 2 divisors, whose sum is σ = 644142. Its totient is φ = 644140.

The previous prime is 644131. The next prime is 644143. The reversal of 644141 is 141446.

It is a happy number.

644141 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 568516 + 75625 = 754^2 + 275^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-644141 is a prime.

Together with 644143, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322070 + 322071.

It is an arithmetic number, because the mean of its divisors is an integer number (322071).

2⁶⁴⁴¹⁴¹ is an apocalyptic number.

It is an amenable number.

644141 is a deficient number, since it is larger than the sum of its proper divisors (1).

644141 is an equidigital number, since it uses as much as digits as its factorization.

644141 is an evil number, because the sum of its binary digits is even.

The product of its digits is 384, while the sum is 20.

The square root of 644141 is about 802.5839519951. The cubic root of 644141 is about 86.3628530442.

Adding to 644141 its reverse (141446), we get a palindrome (785587).

The spelling of 644141 in words is "six hundred forty-four thousand, one hundred forty-one".