18111540 has 48 divisors (see below), whose sum is σ = 51367680. Its totient is φ = 4767360.

The previous prime is 18111539. The next prime is 18111547. The reversal of 18111540 is 4511181.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18111547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2830 + ... + 6650.

It is an arithmetic number, because the mean of its divisors is an integer number (1070160).

Almost surely, 2^18111540 is an apocalyptic number.

18111540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18111540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25683840).

18111540 is an abundant number, since it is smaller than the sum of its proper divisors (33256140).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18111540 is a wasteful number, since it uses less digits than its factorization.

18111540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3912 (or 3910 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 21.

The square root of 18111540 is about 4255.7655010585. The cubic root of 18111540 is about 262.6143538045.

The spelling of 18111540 in words is "eighteen million, one hundred eleven thousand, five hundred forty".