18121116 has 48 divisors (see below), whose sum is σ = 48220704. Its totient is φ = 5246976.

The previous prime is 18121093. The next prime is 18121123. The reversal of 18121116 is 61112181.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18121092 and 18121101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 765 + ... + 6068.

It is an arithmetic number, because the mean of its divisors is an integer number (1004598).

Almost surely, 2^18121116 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18121116, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24110352).

18121116 is an abundant number, since it is smaller than the sum of its proper divisors (30099588).

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

18121116 is a wasteful number, since it uses less digits than its factorization.

18121116 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6870 (or 6868 counting only the distinct ones).

The product of its digits is 96, while the sum is 21.

The square root of 18121116 is about 4256.8904143753. The cubic root of 18121116 is about 262.6606291253.

Adding to 18121116 its reverse (61112181), we get a palindrome (79233297).

The spelling of 18121116 in words is "eighteen million, one hundred twenty-one thousand, one hundred sixteen".