81909070909186 has 8 divisors (see below), whose sum is σ = 122863649861520. Its totient is φ = 40954520955348.

The previous prime is 81909070909157. The next prime is 81909070909207. The reversal of 81909070909186 is 68190907090918.

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 (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2358825 + ... + 13014691.

It is an arithmetic number, because the mean of its divisors is an integer number (15357956232690).

Almost surely, 2^{81909070909186} is an apocalyptic number.

81909070909186 is a deficient number, since it is larger than the sum of its proper divisors (40954578952334).

81909070909186 is a wasteful number, since it uses less digits than its factorization.

81909070909186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14499248.

The product of its (nonzero) digits is 17635968, while the sum is 67.

The spelling of 81909070909186 in words is "eighty-one trillion, nine hundred nine billion, seventy million, nine hundred nine thousand, one hundred eighty-six".