18380440 has 48 divisors (see below), whose sum is σ = 44798400. Its totient is φ = 6784128.

The previous prime is 18380437. The next prime is 18380449. The reversal of 18380440 is 4408381.

It is a junction number, because it is equal to n+sod(n) for n = 18380399 and 18380408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18380449) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 5401 + ... + 8119.

It is an arithmetic number, because the mean of its divisors is an integer number (933300).

Almost surely, 2^18380440 is an apocalyptic number.

18380440 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 18380440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22399200).

18380440 is an abundant number, since it is smaller than the sum of its proper divisors (26417960).

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

18380440 is a wasteful number, since it uses less digits than its factorization.

18380440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756 (or 2739 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 18380440 is about 4287.2415373991. The cubic root of 18380440 is about 263.9076429310.

The spelling of 18380440 in words is "eighteen million, three hundred eighty thousand, four hundred forty".