65243634221 has 2 divisors, whose sum is σ = 65243634222. Its totient is φ = 65243634220.

The previous prime is 65243634151. The next prime is 65243634271. The reversal of 65243634221 is 12243634256.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34569964900 + 30673669321 = 185930^2 + 175139^2 .

It is a cyclic number.

It is not a de Polignac number, because 65243634221 - 2¹⁰ = 65243633197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (65243634271) 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, 32621817110 + 32621817111.

It is an arithmetic number, because the mean of its divisors is an integer number (32621817111).

Almost surely, 2^65243634221 is an apocalyptic number.

It is an amenable number.

65243634221 is a deficient number, since it is larger than the sum of its proper divisors (1).

65243634221 is an equidigital number, since it uses as much as digits as its factorization.

65243634221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 207360, while the sum is 38.

The spelling of 65243634221 in words is "sixty-five billion, two hundred forty-three million, six hundred thirty-four thousand, two hundred twenty-one".