18187740 has 120 divisors (see below), whose sum is σ = 58138080. Its totient is φ = 4758912.

The previous prime is 18187717. The next prime is 18187751. The reversal of 18187740 is 4778181.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18187695 and 18187704.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 166806 + ... + 166914.

It is an arithmetic number, because the mean of its divisors is an integer number (484484).

Almost surely, 2^18187740 is an apocalyptic number.

18187740 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 18187740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29069040).

18187740 is an abundant number, since it is smaller than the sum of its proper divisors (39950340).

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

18187740 is a wasteful number, since it uses less digits than its factorization.

18187740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 233 (or 222 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 18187740 is about 4264.7086653135. The cubic root of 18187740 is about 262.9821343288.

The spelling of 18187740 in words is "eighteen million, one hundred eighty-seven thousand, seven hundred forty".