18381316 has 24 divisors (see below), whose sum is σ = 33003936. Its totient is φ = 8954880.

The previous prime is 18381287. The next prime is 18381317. The reversal of 18381316 is 61318381.

It is not an unprimeable number, because it can be changed into a prime (18381317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28356 + ... + 28996.

It is an arithmetic number, because the mean of its divisors is an integer number (1375164).

Almost surely, 2^18381316 is an apocalyptic number.

It is an amenable number.

18381316 is a deficient number, since it is larger than the sum of its proper divisors (14622620).

18381316 is a wasteful number, since it uses less digits than its factorization.

18381316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819 (or 817 counting only the distinct ones).

The product of its digits is 3456, while the sum is 31.

The square root of 18381316 is about 4287.3436997750. The cubic root of 18381316 is about 263.9118354209.

Adding to 18381316 its reverse (61318381), we get a palindrome (79699697).

The spelling of 18381316 in words is "eighteen million, three hundred eighty-one thousand, three hundred sixteen".