18205920 has 144 divisors (see below), whose sum is σ = 63685440. Its totient is φ = 4733952.

The previous prime is 18205909. The next prime is 18205937. The reversal of 18205920 is 2950281.

It is a tau number, because it is divible by the number of its divisors (144).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 67546 + ... + 67814.

It is an arithmetic number, because the mean of its divisors is an integer number (442260).

Almost surely, 2^18205920 is an apocalyptic number.

18205920 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 18205920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31842720).

18205920 is an abundant number, since it is smaller than the sum of its proper divisors (45479520).

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

18205920 is a wasteful number, since it uses less digits than its factorization.

18205920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The square root of 18205920 is about 4266.8395798295. The cubic root of 18205920 is about 263.0697285561.

The spelling of 18205920 in words is "eighteen million, two hundred five thousand, nine hundred twenty".