18448390325581 has 2 divisors, whose sum is σ = 18448390325582. Its totient is φ = 18448390325580.

The previous prime is 18448390325557. The next prime is 18448390325611. The reversal of 18448390325581 is 18552309384481.

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., 15381566300356 + 3066824025225 = 3921934^2 + 1751235^2 .

It is a cyclic number.

It is not a de Polignac number, because 18448390325581 - 2²¹ = 18448388228429 is a prime.

It is a super-2 number, since 2×18448390325581² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18448390325501) 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, 9224195162790 + 9224195162791.

It is an arithmetic number, because the mean of its divisors is an integer number (9224195162791).

Almost surely, 2^{18448390325581} is an apocalyptic number.

It is an amenable number.

18448390325581 is a deficient number, since it is larger than the sum of its proper divisors (1).

18448390325581 is an equidigital number, since it uses as much as digits as its factorization.

18448390325581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 33177600, while the sum is 61.

The spelling of 18448390325581 in words is "eighteen trillion, four hundred forty-eight billion, three hundred ninety million, three hundred twenty-five thousand, five hundred eighty-one".