18440111 has 2 divisors, whose sum is σ = 18440112. Its totient is φ = 18440110.

The previous prime is 18440047. The next prime is 18440129. The reversal of 18440111 is 11104481.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18440111 - 2⁶ = 18440047 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18440141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9220055 + 9220056.

It is an arithmetic number, because the mean of its divisors is an integer number (9220056).

Almost surely, 2^18440111 is an apocalyptic number.

18440111 is a deficient number, since it is larger than the sum of its proper divisors (1).

18440111 is an equidigital number, since it uses as much as digits as its factorization.

18440111 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 20.

The square root of 18440111 is about 4294.1950351608. The cubic root of 18440111 is about 264.1929212374.

Adding to 18440111 its reverse (11104481), we get a palindrome (29544592).

The spelling of 18440111 in words is "eighteen million, four hundred forty thousand, one hundred eleven".