81818186 has 8 divisors (see below), whose sum is σ = 123008160. Its totient is φ = 40815468.

The previous prime is 81818179. The next prime is 81818197. The reversal of 81818186 is 68181818.

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, 45716 + ... + 47471.

It is an arithmetic number, because the mean of its divisors is an integer number (15376020).

Almost surely, 2^81818186 is an apocalyptic number.

81818186 is a deficient number, since it is larger than the sum of its proper divisors (41189974).

81818186 is a wasteful number, since it uses less digits than its factorization.

81818186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93628.

The product of its digits is 24576, while the sum is 41.

The square root of 81818186 is about 9045.3405684916. The cubic root of 81818186 is about 434.1268184679.

The spelling of 81818186 in words is "eighty-one million, eight hundred eighteen thousand, one hundred eighty-six".