81518967416 has 8 divisors (see below), whose sum is σ = 152848063920. Its totient is φ = 40759483704.

The previous prime is 81518967401. The next prime is 81518967419. The reversal of 81518967416 is 61476981518.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81518967419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5094935456 + ... + 5094935471.

It is an arithmetic number, because the mean of its divisors is an integer number (19106007990).

Almost surely, 2^81518967416 is an apocalyptic number.

It is an amenable number.

81518967416 is a deficient number, since it is larger than the sum of its proper divisors (71329096504).

81518967416 is a wasteful number, since it uses less digits than its factorization.

81518967416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10189870933 (or 10189870929 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 56.

The spelling of 81518967416 in words is "eighty-one billion, five hundred eighteen million, nine hundred sixty-seven thousand, four hundred sixteen".