641345126221 has 2 divisors, whose sum is σ = 641345126222. Its totient is φ = 641345126220.

The previous prime is 641345126209. The next prime is 641345126251. The reversal of 641345126221 is 122621543146.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 571588921225 + 69756204996 = 756035^2 + 264114^2 .

It is a cyclic number.

It is not a de Polignac number, because 641345126221 - 2¹⁵ = 641345093453 is a prime.

It is a super-2 number, since 2×641345126221² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (641345126251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320672563110 + 320672563111.

It is an arithmetic number, because the mean of its divisors is an integer number (320672563111).

Almost surely, 2^641345126221 is an apocalyptic number.

It is an amenable number.

641345126221 is a deficient number, since it is larger than the sum of its proper divisors (1).

641345126221 is an equidigital number, since it uses as much as digits as its factorization.

641345126221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 37.

Adding to 641345126221 its reverse (122621543146), we get a palindrome (763966669367).

The spelling of 641345126221 in words is "six hundred forty-one billion, three hundred forty-five million, one hundred twenty-six thousand, two hundred twenty-one".