81115659211 has 4 divisors (see below), whose sum is σ = 81873749592. Its totient is φ = 80357568832.

The previous prime is 81115659187. The next prime is 81115659223. The reversal of 81115659211 is 11295651118.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81115659211 - 2⁹ = 81115658699 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81115659241) by changing a digit.

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, 379045030 + ... + 379045243.

It is an arithmetic number, because the mean of its divisors is an integer number (20468437398).

Almost surely, 2^81115659211 is an apocalyptic number.

81115659211 is a deficient number, since it is larger than the sum of its proper divisors (758090381).

81115659211 is a wasteful number, since it uses less digits than its factorization.

81115659211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758090380.

The product of its digits is 21600, while the sum is 40.

The spelling of 81115659211 in words is "eighty-one billion, one hundred fifteen million, six hundred fifty-nine thousand, two hundred eleven".