18855911 has 2 divisors, whose sum is σ = 18855912. Its totient is φ = 18855910.

The previous prime is 18855899. The next prime is 18855917. The reversal of 18855911 is 11955881.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18855911 is a 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 (18855917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9427955 + 9427956.

It is an arithmetic number, because the mean of its divisors is an integer number (9427956).

Almost surely, 2^18855911 is an apocalyptic number.

18855911 is a deficient number, since it is larger than the sum of its proper divisors (1).

18855911 is an equidigital number, since it uses as much as digits as its factorization.

18855911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14400, while the sum is 38.

The square root of 18855911 is about 4342.3393464813. The cubic root of 18855911 is about 266.1639133325.

The spelling of 18855911 in words is "eighteen million, eight hundred fifty-five thousand, nine hundred eleven".