20181330 has 96 divisors (see below), whose sum is σ = 57867264. Its totient is φ = 4848768.

The previous prime is 20181323. The next prime is 20181347. The reversal of 20181330 is 3318102.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 54807 + ... + 55173.

It is an arithmetic number, because the mean of its divisors is an integer number (602784).

Almost surely, 2^20181330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20181330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28933632).

20181330 is an abundant number, since it is smaller than the sum of its proper divisors (37685934).

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

20181330 is a wasteful number, since it uses less digits than its factorization.

20181330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 437 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 20181330 is about 4492.3635204645. The cubic root of 20181330 is about 272.2596371052.

Adding to 20181330 its reverse (3318102), we get a palindrome (23499432).

The spelling of 20181330 in words is "twenty million, one hundred eighty-one thousand, three hundred thirty".