18339940 has 72 divisors (see below), whose sum is σ = 43323840. Its totient is φ = 6501888.

The previous prime is 18339913. The next prime is 18340019. The reversal of 18339940 is 4993381.

It is a self number, because there is not a number n which added to its sum of digits gives 18339940.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 109737 + ... + 109903.

It is an arithmetic number, because the mean of its divisors is an integer number (601720).

Almost surely, 2^18339940 is an apocalyptic number.

18339940 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 18339940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21661920).

18339940 is an abundant number, since it is smaller than the sum of its proper divisors (24983900).

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

18339940 is a wasteful number, since it uses less digits than its factorization.

18339940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 210 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 18339940 is about 4282.5156158501. The cubic root of 18339940 is about 263.7136664459.

The spelling of 18339940 in words is "eighteen million, three hundred thirty-nine thousand, nine hundred forty".