18919240169 has 2 divisors, whose sum is σ = 18919240170. Its totient is φ = 18919240168.

The previous prime is 18919240159. The next prime is 18919240183. The reversal of 18919240169 is 96104291981.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11154105769 + 7765134400 = 105613^2 + 88120^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18919240169 is a prime.

It is a super-2 number, since 2×18919240169² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (18919240159) 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, 9459620084 + 9459620085.

It is an arithmetic number, because the mean of its divisors is an integer number (9459620085).

Almost surely, 2^18919240169 is an apocalyptic number.

It is an amenable number.

18919240169 is a deficient number, since it is larger than the sum of its proper divisors (1).

18919240169 is an equidigital number, since it uses as much as digits as its factorization.

18919240169 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 50.

The spelling of 18919240169 in words is "eighteen billion, nine hundred nineteen million, two hundred forty thousand, one hundred sixty-nine".