81718281718 has 8 divisors (see below), whose sum is σ = 122739350112. Its totient is φ = 40805165016.

The previous prime is 81718281683. The next prime is 81718281719.

It is a happy number.

81718281718 is nontrivially palindromic in base 10.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81718281719) 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 3 ways as a sum of consecutive naturals, for example, 26986030 + ... + 26989057.

It is an arithmetic number, because the mean of its divisors is an integer number (15342418764).

Almost surely, 2^81718281718 is an apocalyptic number.

81718281718 is a deficient number, since it is larger than the sum of its proper divisors (41021068394).

81718281718 is a wasteful number, since it uses less digits than its factorization.

81718281718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53975846.

The product of its digits is 401408, while the sum is 52.

The spelling of 81718281718 in words is "eighty-one billion, seven hundred eighteen million, two hundred eighty-one thousand, seven hundred eighteen".