17421967621 has 2 divisors, whose sum is σ = 17421967622. Its totient is φ = 17421967620.

The previous prime is 17421967579. The next prime is 17421967657. The reversal of 17421967621 is 12676912471.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17060016996 + 361950625 = 130614^2 + 19025^2 .

It is an emirp because it is prime and its reverse (12676912471) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 17421967621 - 2²¹ = 17419870469 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17421964621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8710983810 + 8710983811.

It is an arithmetic number, because the mean of its divisors is an integer number (8710983811).

Almost surely, 2^17421967621 is an apocalyptic number.

It is an amenable number.

17421967621 is a deficient number, since it is larger than the sum of its proper divisors (1).

17421967621 is an equidigital number, since it uses as much as digits as its factorization.

17421967621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 254016, while the sum is 46.

The spelling of 17421967621 in words is "seventeen billion, four hundred twenty-one million, nine hundred sixty-seven thousand, six hundred twenty-one".