18135911 has 4 divisors (see below), whose sum is σ = 18478152. Its totient is φ = 17793672.

The previous prime is 18135907. The next prime is 18135917. The reversal of 18135911 is 11953181.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18135911 - 2² = 18135907 is a prime.

It is a super-2 number, since 2×18135911² = 657822535599842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18135917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171041 + ... + 171146.

It is an arithmetic number, because the mean of its divisors is an integer number (4619538).

Almost surely, 2^18135911 is an apocalyptic number.

18135911 is a deficient number, since it is larger than the sum of its proper divisors (342241).

18135911 is an equidigital number, since it uses as much as digits as its factorization.

18135911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 342240.

The product of its digits is 1080, while the sum is 29.

The square root of 18135911 is about 4258.6278306516. The cubic root of 18135911 is about 262.7320928419.

The spelling of 18135911 in words is "eighteen million, one hundred thirty-five thousand, nine hundred eleven".