2181686818 has 8 divisors (see below), whose sum is σ = 3444768720. Its totient is φ = 1033430580.

The previous prime is 2181686809. The next prime is 2181686851. The reversal of 2181686818 is 8186861812.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28706368 + ... + 28706443.

It is an arithmetic number, because the mean of its divisors is an integer number (430596090).

Almost surely, 2^2181686818 is an apocalyptic number.

2181686818 is a deficient number, since it is larger than the sum of its proper divisors (1263081902).

2181686818 is a wasteful number, since it uses less digits than its factorization.

2181686818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57412832.

The product of its digits is 294912, while the sum is 49.

The square root of 2181686818 is about 46708.5304628608. The cubic root of 2181686818 is about 1296.9726038956.

The spelling of 2181686818 in words is "two billion, one hundred eighty-one million, six hundred eighty-six thousand, eight hundred eighteen".