18385780 has 72 divisors (see below), whose sum is σ = 45706248. Its totient is φ = 6193152.

The previous prime is 18385771. The next prime is 18385819. The reversal of 18385780 is 8758381.

It can be written as a sum of positive squares in 4 ways, for example, as 7376656 + 11009124 = 2716^2 + 3318^2 .

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, 71412 + ... + 71668.

It is an arithmetic number, because the mean of its divisors is an integer number (634809).

Almost surely, 2^18385780 is an apocalyptic number.

18385780 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 18385780, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22853124).

18385780 is an abundant number, since it is smaller than the sum of its proper divisors (27320468).

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

18385780 is a wasteful number, since it uses less digits than its factorization.

18385780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 40.

The square root of 18385780 is about 4287.8642702399. The cubic root of 18385780 is about 263.9331978209.

The spelling of 18385780 in words is "eighteen million, three hundred eighty-five thousand, seven hundred eighty".