111618809 has 2 divisors, whose sum is σ = 111618810. Its totient is φ = 111618808.

The previous prime is 111618803. The next prime is 111618811. The reversal of 111618809 is 908816111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 96040000 + 15578809 = 9800^2 + 3947^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111618809 is a prime.

Together with 111618811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (111618803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55809404 + 55809405.

It is an arithmetic number, because the mean of its divisors is an integer number (55809405).

Almost surely, 2^111618809 is an apocalyptic number.

It is an amenable number.

111618809 is a deficient number, since it is larger than the sum of its proper divisors (1).

111618809 is an equidigital number, since it uses as much as digits as its factorization.

111618809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 35.

The square root of 111618809 is about 10564.9803123338. The cubic root of 111618809 is about 481.4809714033.

The spelling of 111618809 in words is "one hundred eleven million, six hundred eighteen thousand, eight hundred nine".