99818181 has 12 divisors (see below), whose sum is σ = 144356940. Its totient is φ = 66464640.

The previous prime is 99818129. The next prime is 99818189. The reversal of 99818181 is 18181899.

It can be written as a sum of positive squares in 2 ways, for example, as 12489156 + 87329025 = 3534^2 + 9345^2 .

It is not a de Polignac number, because 99818181 - 2¹¹ = 99816133 is a prime.

It is a super-2 number, since 2×99818181² = 19927338516297522, which contains 22 as substring.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

99818181 is a modest number, since divided by 818181 gives 99 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99818189) 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, 1635 + ... + 14223.

It is an arithmetic number, because the mean of its divisors is an integer number (12029745).

Almost surely, 2^99818181 is an apocalyptic number.

It is an amenable number.

99818181 is a deficient number, since it is larger than the sum of its proper divisors (44538759).

99818181 is a wasteful number, since it uses less digits than its factorization.

99818181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13476 (or 13473 counting only the distinct ones).

The product of its digits is 41472, while the sum is 45.

The square root of 99818181 is about 9990.9049139705. The cubic root of 99818181 is about 463.8774030173.

It can be divided in two parts, 99818 and 181, that added together give a palindrome (99999).

The spelling of 99818181 in words is "ninety-nine million, eight hundred eighteen thousand, one hundred eighty-one".