18021088866449 has 2 divisors, whose sum is σ = 18021088866450. Its totient is φ = 18021088866448.

The previous prime is 18021088866433. The next prime is 18021088866523. The reversal of 18021088866449 is 94466888012081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15429655363600 + 2591433502849 = 3928060^2 + 1609793^2 .

It is a cyclic number.

It is not a de Polignac number, because 18021088866449 - 2⁴ = 18021088866433 is a prime.

It is not a weakly prime, because it can be changed into another prime (18021088865449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9010544433224 + 9010544433225.

It is an arithmetic number, because the mean of its divisors is an integer number (9010544433225).

Almost surely, 2^{18021088866449} is an apocalyptic number.

It is an amenable number.

18021088866449 is a deficient number, since it is larger than the sum of its proper divisors (1).

18021088866449 is an equidigital number, since it uses as much as digits as its factorization.

18021088866449 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42467328, while the sum is 65.

The spelling of 18021088866449 in words is "eighteen trillion, twenty-one billion, eighty-eight million, eight hundred sixty-six thousand, four hundred forty-nine".