111761815837781 has 2 divisors, whose sum is σ = 111761815837782. Its totient is φ = 111761815837780.

The previous prime is 111761815837759. The next prime is 111761815837801. The reversal of 111761815837781 is 187738518167111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 69444722222500 + 42317093615281 = 8333350^2 + 6505159^2 .

It is a cyclic number.

It is not a de Polignac number, because 111761815837781 - 2⁶ = 111761815837717 is a prime.

It is a super-2 number, since 2×111761815837781² (a number of 29 digits) contains 22 as substring.

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 (111761815837741) 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, 55880907918890 + 55880907918891.

It is an arithmetic number, because the mean of its divisors is an integer number (55880907918891).

Almost surely, 2^{111761815837781} is an apocalyptic number.

It is an amenable number.

111761815837781 is a deficient number, since it is larger than the sum of its proper divisors (1).

111761815837781 is an equidigital number, since it uses as much as digits as its factorization.

111761815837781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15805440, while the sum is 65.

The spelling of 111761815837781 in words is "one hundred eleven trillion, seven hundred sixty-one billion, eight hundred fifteen million, eight hundred thirty-seven thousand, seven hundred eighty-one".