641549 has 2 divisors, whose sum is σ = 641550. Its totient is φ = 641548.

The previous prime is 641521. The next prime is 641551. The reversal of 641549 is 945146.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 515524 + 126025 = 718^2 + 355^2 .

It is a cyclic number.

It is not a de Polignac number, because 641549 - 2¹⁶ = 576013 is a prime.

It is a Sophie Germain prime.

Together with 641551, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320774 + 320775.

It is an arithmetic number, because the mean of its divisors is an integer number (320775).

2⁶⁴¹⁵⁴⁹ is an apocalyptic number.

It is an amenable number.

641549 is a deficient number, since it is larger than the sum of its proper divisors (1).

641549 is an equidigital number, since it uses as much as digits as its factorization.

641549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 29.

The square root of 641549 is about 800.9675399166. The cubic root of 641549 is about 86.2468569883.

The spelling of 641549 in words is "six hundred forty-one thousand, five hundred forty-nine".