18380416 has 32 divisors (see below), whose sum is σ = 37616580. Its totient is φ = 8939520.

The previous prime is 18380413. The next prime is 18380419. The reversal of 18380416 is 61408381.

It is an interprime number because it is at equal distance from previous prime (18380413) and next prime (18380419).

It can be written as a sum of positive squares in 2 ways, for example, as 16842816 + 1537600 = 4104^2 + 1240^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (18380413) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2796 + ... + 6676.

Almost surely, 2^18380416 is an apocalyptic number.

18380416 is a gapful number since it is divisible by the number (16) 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 18380416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18808290).

18380416 is an abundant number, since it is smaller than the sum of its proper divisors (19236164).

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

18380416 is an equidigital number, since it uses as much as digits as its factorization.

18380416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3932 (or 3920 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 18380416 is about 4287.2387383956. The cubic root of 18380416 is about 263.9075280664.

Adding to 18380416 its reverse (61408381), we get a palindrome (79788797).

The spelling of 18380416 in words is "eighteen million, three hundred eighty thousand, four hundred sixteen".