18181098 has 80 divisors (see below), whose sum is σ = 44823240. Its totient is φ = 5474304.

The previous prime is 18181039. The next prime is 18181103. The reversal of 18181098 is 89018181.

It can be written as a sum of positive squares in 4 ways, for example, as 9199089 + 8982009 = 3033^2 + 2997^2 .

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 187386 + ... + 187482.

Almost surely, 2^18181098 is an apocalyptic number.

18181098 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18181098, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22411620).

18181098 is an abundant number, since it is smaller than the sum of its proper divisors (26642142).

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

18181098 is a wasteful number, since it uses less digits than its factorization.

18181098 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 213 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 36.

The square root of 18181098 is about 4263.9298774722. The cubic root of 18181098 is about 262.9501175232.

It can be divided in two parts, 1818 and 1098, that added together give a square (2916 = 54²).

The spelling of 18181098 in words is "eighteen million, one hundred eighty-one thousand, ninety-eight".