81118121668 has 12 divisors (see below), whose sum is σ = 142147776960. Its totient is φ = 40504471112.

The previous prime is 81118121597. The next prime is 81118121681. The reversal of 81118121668 is 86612181118.

It is a super-2 number, since 2×81118121668² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13644088 + ... + 13650031.

It is an arithmetic number, because the mean of its divisors is an integer number (11845648080).

Almost surely, 2^81118121668 is an apocalyptic number.

It is an amenable number.

81118121668 is a deficient number, since it is larger than the sum of its proper divisors (61029655292).

81118121668 is a wasteful number, since it uses less digits than its factorization.

81118121668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27294866 (or 27294864 counting only the distinct ones).

The product of its digits is 36864, while the sum is 43.

The spelling of 81118121668 in words is "eighty-one billion, one hundred eighteen million, one hundred twenty-one thousand, six hundred sixty-eight".