181105109 has 2 divisors, whose sum is σ = 181105110. Its totient is φ = 181105108.

The previous prime is 181105091. The next prime is 181105139. The reversal of 181105109 is 901501181.

Together with previous prime (181105091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 100500625 + 80604484 = 10025^2 + 8978^2 .

It is a cyclic number.

It is not a de Polignac number, because 181105109 - 2⁸ = 181104853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (181105139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90552554 + 90552555.

It is an arithmetic number, because the mean of its divisors is an integer number (90552555).

Almost surely, 2^181105109 is an apocalyptic number.

It is an amenable number.

181105109 is a deficient number, since it is larger than the sum of its proper divisors (1).

181105109 is an equidigital number, since it uses as much as digits as its factorization.

181105109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 26.

The square root of 181105109 is about 13457.5298253431. The cubic root of 181105109 is about 565.7747577330.

The spelling of 181105109 in words is "one hundred eighty-one million, one hundred five thousand, one hundred nine".