111868509173 has 2 divisors, whose sum is σ = 111868509174. Its totient is φ = 111868509172.

The previous prime is 111868509169. The next prime is 111868509223. The reversal of 111868509173 is 371905868111.

It is an a-pointer prime, because the next prime (111868509223) can be obtained adding 111868509173 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111303638884 + 564870289 = 333622^2 + 23767^2 .

It is a cyclic number.

It is not a de Polignac number, because 111868509173 - 2² = 111868509169 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111868500173) 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, 55934254586 + 55934254587.

It is an arithmetic number, because the mean of its divisors is an integer number (55934254587).

Almost surely, 2^111868509173 is an apocalyptic number.

It is an amenable number.

111868509173 is a deficient number, since it is larger than the sum of its proper divisors (1).

111868509173 is an equidigital number, since it uses as much as digits as its factorization.

111868509173 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 362880, while the sum is 50.

The spelling of 111868509173 in words is "one hundred eleven billion, eight hundred sixty-eight million, five hundred nine thousand, one hundred seventy-three".