641135056621 has 2 divisors, whose sum is σ = 641135056622. Its totient is φ = 641135056620.

The previous prime is 641135056613. The next prime is 641135056697. The reversal of 641135056621 is 126650531146.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 490439698596 + 150695358025 = 700314^2 + 388195^2 .

It is a cyclic number.

It is not a de Polignac number, because 641135056621 - 2³ = 641135056613 is a prime.

It is a super-2 number, since 2×641135056621² (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 (641135056021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320567528310 + 320567528311.

It is an arithmetic number, because the mean of its divisors is an integer number (320567528311).

Almost surely, 2^641135056621 is an apocalyptic number.

It is an amenable number.

641135056621 is a deficient number, since it is larger than the sum of its proper divisors (1).

641135056621 is an equidigital number, since it uses as much as digits as its factorization.

641135056621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 129600, while the sum is 40.

Adding to 641135056621 its reverse (126650531146), we get a palindrome (767785587767).

The spelling of 641135056621 in words is "six hundred forty-one billion, one hundred thirty-five million, fifty-six thousand, six hundred twenty-one".