18380205 has 24 divisors (see below), whose sum is σ = 32014008. Its totient is φ = 9755136.

The previous prime is 18380203. The next prime is 18380233. The reversal of 18380205 is 50208381.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 385641 + 17994564 = 621^2 + 4242^2 .

It is not a de Polignac number, because 18380205 - 2¹ = 18380203 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18380203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9609 + ... + 11361.

It is an arithmetic number, because the mean of its divisors is an integer number (1333917).

Almost surely, 2^18380205 is an apocalyptic number.

18380205 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18380205 is a deficient number, since it is larger than the sum of its proper divisors (13633803).

18380205 is a wasteful number, since it uses less digits than its factorization.

18380205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1997 (or 1994 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 18380205 is about 4287.2141304115. The cubic root of 18380205 is about 263.9065182108.

Adding to 18380205 its reverse (50208381), we get a palindrome (68588586).

The spelling of 18380205 in words is "eighteen million, three hundred eighty thousand, two hundred five".