18181818181 has 8 divisors (see below), whose sum is σ = 19156680800. Its totient is φ = 17208748080.

The previous prime is 18181818119. The next prime is 18181818209.

It is a happy number.

18181818181 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18181818181 is a prime.

It is a super-2 number, since 2×18181818181² (a number of 21 digits) contains 22 as substring.

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

18181818181 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

18181818181 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 (18181888181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 427275 + ... + 467896.

It is an arithmetic number, because the mean of its divisors is an integer number (2394585100).

Almost surely, 2^18181818181 is an apocalyptic number.

It is an amenable number.

18181818181 is a deficient number, since it is larger than the sum of its proper divisors (974862619).

18181818181 is a wasteful number, since it uses less digits than its factorization.

18181818181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 896259.

The product of its digits is 32768, while the sum is 46.

The spelling of 18181818181 in words is "eighteen billion, one hundred eighty-one million, eight hundred eighteen thousand, one hundred eighty-one".