641813 has 2 divisors, whose sum is σ = 641814. Its totient is φ = 641812.

The previous prime is 641803. The next prime is 641819. The reversal of 641813 is 318146.

641813 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., 432964 + 208849 = 658^2 + 457^2 .

It is a cyclic number.

It is not a de Polignac number, because 641813 - 2⁶ = 641749 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320906 + 320907.

It is an arithmetic number, because the mean of its divisors is an integer number (320907).

2⁶⁴¹⁸¹³ is an apocalyptic number.

It is an amenable number.

641813 is a deficient number, since it is larger than the sum of its proper divisors (1).

641813 is an equidigital number, since it uses as much as digits as its factorization.

641813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 23.

The square root of 641813 is about 801.1323236520. The cubic root of 641813 is about 86.2586856757.

Adding to 641813 its reverse (318146), we get a palindrome (959959).

The spelling of 641813 in words is "six hundred forty-one thousand, eight hundred thirteen".