181818181818181 has 16 divisors (see below), whose sum is σ = 188131514457600. Its totient is φ = 175507769248000.

The previous prime is 181818181818121. The next prime is 181818181818191.

181818181818181 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 181818181818181 - 2⁹ = 181818181817669 is a prime.

It is a super-2 number, since 2×181818181818181² (a number of 29 digits) contains 22 as substring.

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

181818181818181 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

181818181818181 is an undulating number in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (181818181818121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4569309396 + ... + 4569349186.

It is an arithmetic number, because the mean of its divisors is an integer number (11758219653600).

Almost surely, 2^{181818181818181} is an apocalyptic number.

It is an amenable number.

181818181818181 is a deficient number, since it is larger than the sum of its proper divisors (6313332639419).

181818181818181 is a wasteful number, since it uses less digits than its factorization.

181818181818181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72500.

The product of its digits is 2097152, while the sum is 64.

The spelling of 181818181818181 in words is "one hundred eighty-one trillion, eight hundred eighteen billion, one hundred eighty-one million, eight hundred eighteen thousand, one hundred eighty-one".