18420322773649 has 2 divisors, whose sum is σ = 18420322773650. Its totient is φ = 18420322773648.

The previous prime is 18420322773647. The next prime is 18420322773739. The reversal of 18420322773649 is 94637722302481.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18356297580625 + 64025193024 = 4284425^2 + 253032^2 .

It is an emirp because it is prime and its reverse (94637722302481) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 18420322773649 - 2¹ = 18420322773647 is a prime.

Together with 18420322773647, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 18420322773593 and 18420322773602.

It is not a weakly prime, because it can be changed into another prime (18420322773647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9210161386824 + 9210161386825.

It is an arithmetic number, because the mean of its divisors is an integer number (9210161386825).

Almost surely, 2^{18420322773649} is an apocalyptic number.

It is an amenable number.

18420322773649 is a deficient number, since it is larger than the sum of its proper divisors (1).

18420322773649 is an equidigital number, since it uses as much as digits as its factorization.

18420322773649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24385536, while the sum is 58.

The spelling of 18420322773649 in words is "eighteen trillion, four hundred twenty billion, three hundred twenty-two million, seven hundred seventy-three thousand, six hundred forty-nine".