18112509 has 12 divisors (see below), whose sum is σ = 26478816. Its totient is φ = 11929032.

The previous prime is 18112487. The next prime is 18112511. The reversal of 18112509 is 90521181.

It is not a de Polignac number, because 18112509 - 2⁸ = 18112253 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18112009) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11377 + ... + 12870.

It is an arithmetic number, because the mean of its divisors is an integer number (2206568).

Almost surely, 2^18112509 is an apocalyptic number.

It is an amenable number.

18112509 is a deficient number, since it is larger than the sum of its proper divisors (8366307).

18112509 is a wasteful number, since it uses less digits than its factorization.

18112509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24336 (or 24333 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 18112509 is about 4255.8793450943. The cubic root of 18112509 is about 262.6190371679.

The spelling of 18112509 in words is "eighteen million, one hundred twelve thousand, five hundred nine".