181818900 has 54 divisors (see below), whose sum is σ = 569904062. Its totient is φ = 48484800.

The previous prime is 181818869. The next prime is 181818913. The reversal of 181818900 is 9818181.

It can be written as a sum of positive squares in 3 ways, for example, as 10575504 + 171243396 = 3252^2 + 13086^2 .

It is a super-2 number, since 2×181818900² = 66116224794420000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 100111 + ... + 101910.

Almost surely, 2^181818900 is an apocalyptic number.

181818900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

181818900 is an abundant number, since it is smaller than the sum of its proper divisors (388085162).

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

181818900 is a wasteful number, since it uses less digits than its factorization.

181818900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202041 (or 202031 counting only the distinct ones).

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

The square root of 181818900 is about 13484.0238801331. The cubic root of 181818900 is about 566.5170808549.

The spelling of 181818900 in words is "one hundred eighty-one million, eight hundred eighteen thousand, nine hundred".