18100818 has 48 divisors (see below), whose sum is σ = 41909400. Its totient is φ = 5626368.

The previous prime is 18100783. The next prime is 18100837. The reversal of 18100818 is 81800181.

It can be written as a sum of positive squares in 4 ways, for example, as 15657849 + 2442969 = 3957^2 + 1563^2 .

It is a super-2 number, since 2×18100818² = 655279224538248, which contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18100791 and 18100800.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45396 + ... + 45792.

Almost surely, 2^18100818 is an apocalyptic number.

18100818 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 18100818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20954700).

18100818 is an abundant number, since it is smaller than the sum of its proper divisors (23808582).

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

18100818 is a wasteful number, since it uses less digits than its factorization.

18100818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571 (or 568 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 27.

The square root of 18100818 is about 4254.5056117016. The cubic root of 18100818 is about 262.5625211622.

Adding to 18100818 its reverse (81800181), we get a palindrome (99900999).

The spelling of 18100818 in words is "eighteen million, one hundred thousand, eight hundred eighteen".