18109100 has 36 divisors (see below), whose sum is σ = 40143264. Its totient is φ = 7087680.

The previous prime is 18109099. The next prime is 18109103. The reversal of 18109100 is 190181.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (18109103) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2774 + ... + 6626.

Almost surely, 2^18109100 is an apocalyptic number.

18109100 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 18109100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20071632).

18109100 is an abundant number, since it is smaller than the sum of its proper divisors (22034164).

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

18109100 is a wasteful number, since it uses less digits than its factorization.

18109100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3914 (or 3907 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 18109100 is about 4255.4788214724. The cubic root of 18109100 is about 262.6025600752.

Adding to 18109100 its reverse (190181), we get a palindrome (18299281).

The spelling of 18109100 in words is "eighteen million, one hundred nine thousand, one hundred".