641789 has 2 divisors, whose sum is σ = 641790. Its totient is φ = 641788.

The previous prime is 641761. The next prime is 641791. The reversal of 641789 is 987146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 624100 + 17689 = 790^2 + 133^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641789 is a prime.

Together with 641791, 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 (641749) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320894 + 320895.

It is an arithmetic number, because the mean of its divisors is an integer number (320895).

2⁶⁴¹⁷⁸⁹ is an apocalyptic number.

It is an amenable number.

641789 is a deficient number, since it is larger than the sum of its proper divisors (1).

641789 is an equidigital number, since it uses as much as digits as its factorization.

641789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 641789 is about 801.1173447130. The cubic root of 641789 is about 86.2576104746.

The spelling of 641789 in words is "six hundred forty-one thousand, seven hundred eighty-nine".