9421168217621 has 2 divisors, whose sum is σ = 9421168217622. Its totient is φ = 9421168217620.

The previous prime is 9421168217581. The next prime is 9421168217627. The reversal of 9421168217621 is 1267128611249.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5772919236100 + 3648248981521 = 2402690^2 + 1910039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9421168217621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 9421168217621.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9421168217627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4710584108810 + 4710584108811.

It is an arithmetic number, because the mean of its divisors is an integer number (4710584108811).

Almost surely, 2^{9421168217621} is an apocalyptic number.

It is an amenable number.

9421168217621 is a deficient number, since it is larger than the sum of its proper divisors (1).

9421168217621 is an equidigital number, since it uses as much as digits as its factorization.

9421168217621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 580608, while the sum is 50.

The spelling of 9421168217621 in words is "nine trillion, four hundred twenty-one billion, one hundred sixty-eight million, two hundred seventeen thousand, six hundred twenty-one".