17981905111 has 2 divisors, whose sum is σ = 17981905112. Its totient is φ = 17981905110.

The previous prime is 17981905093. The next prime is 17981905133. The reversal of 17981905111 is 11150918971.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 17981905111 - 2²⁷ = 17847687383 is a prime.

It is a super-2 number, since 2×17981905111² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (17981905141) 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, 8990952555 + 8990952556.

It is an arithmetic number, because the mean of its divisors is an integer number (8990952556).

Almost surely, 2^17981905111 is an apocalyptic number.

17981905111 is a deficient number, since it is larger than the sum of its proper divisors (1).

17981905111 is an equidigital number, since it uses as much as digits as its factorization.

17981905111 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 22680, while the sum is 43.

The spelling of 17981905111 in words is "seventeen billion, nine hundred eighty-one million, nine hundred five thousand, one hundred eleven".