18071111 has 2 divisors, whose sum is σ = 18071112. Its totient is φ = 18071110.

The previous prime is 18071107. The next prime is 18071113. The reversal of 18071111 is 11117081.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18071111 - 2² = 18071107 is a prime.

Together with 18071113, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18071113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9035555 + 9035556.

It is an arithmetic number, because the mean of its divisors is an integer number (9035556).

Almost surely, 2^18071111 is an apocalyptic number.

18071111 is a deficient number, since it is larger than the sum of its proper divisors (1).

18071111 is an equidigital number, since it uses as much as digits as its factorization.

18071111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56, while the sum is 20.

The square root of 18071111 is about 4251.0129381125. The cubic root of 18071111 is about 262.4188036096.

Adding to 18071111 its reverse (11117081), we get a palindrome (29188192).

The spelling of 18071111 in words is "eighteen million, seventy-one thousand, one hundred eleven".