18684816 has 80 divisors (see below), whose sum is σ = 51663360. Its totient is φ = 5806080.

The previous prime is 18684773. The next prime is 18684821. The reversal of 18684816 is 61848681.

It is a nude number because it is divisible by every one of its digits.

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 15 ways as a sum of consecutive naturals, for example, 42936 + ... + 43368.

It is an arithmetic number, because the mean of its divisors is an integer number (645792).

Almost surely, 2^18684816 is an apocalyptic number.

18684816 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 18684816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25831680).

18684816 is an abundant number, since it is smaller than the sum of its proper divisors (32978544).

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

18684816 is a wasteful number, since it uses less digits than its factorization.

18684816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504 (or 498 counting only the distinct ones).

The product of its digits is 73728, while the sum is 42.

The square root of 18684816 is about 4322.5936658446. The cubic root of 18684816 is about 265.3564255776.

The spelling of 18684816 in words is "eighteen million, six hundred eighty-four thousand, eight hundred sixteen".