18661424207893 has 2 divisors, whose sum is σ = 18661424207894. Its totient is φ = 18661424207892.

The previous prime is 18661424207851. The next prime is 18661424208023. The reversal of 18661424207893 is 39870242416681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9464864556004 + 9196559651889 = 3076502^2 + 3032583^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18661424207893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18661424207843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9330712103946 + 9330712103947.

It is an arithmetic number, because the mean of its divisors is an integer number (9330712103947).

Almost surely, 2^{18661424207893} is an apocalyptic number.

It is an amenable number.

18661424207893 is a deficient number, since it is larger than the sum of its proper divisors (1).

18661424207893 is an equidigital number, since it uses as much as digits as its factorization.

18661424207893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27869184, while the sum is 61.

The spelling of 18661424207893 in words is "eighteen trillion, six hundred sixty-one billion, four hundred twenty-four million, two hundred seven thousand, eight hundred ninety-three".