81316661318 has 8 divisors (see below), whose sum is σ = 121986841080. Its totient is φ = 40654380960.

The previous prime is 81316661303. The next prime is 81316661381.

81316661318 is nontrivially palindromic in base 10.

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

It is a super-2 number, since 2×81316661318² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1949048 + ... + 1990331.

It is an arithmetic number, because the mean of its divisors is an integer number (15248355135).

Almost surely, 2^81316661318 is an apocalyptic number.

81316661318 is a deficient number, since it is larger than the sum of its proper divisors (40670179762).

81316661318 is a wasteful number, since it uses less digits than its factorization.

81316661318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3949702.

The product of its digits is 124416, while the sum is 44.

The spelling of 81316661318 in words is "eighty-one billion, three hundred sixteen million, six hundred sixty-one thousand, three hundred eighteen".