81768913366 has 12 divisors (see below), whose sum is σ = 142678410228. Its totient is φ = 35043819972.

The previous prime is 81768913363. The next prime is 81768913367. The reversal of 81768913366 is 66331986718.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81768913366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81768913363) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 417188236 + ... + 417188431.

It is an arithmetic number, because the mean of its divisors is an integer number (11889867519).

Almost surely, 2^81768913366 is an apocalyptic number.

81768913366 is a deficient number, since it is larger than the sum of its proper divisors (60909496862).

81768913366 is a wasteful number, since it uses less digits than its factorization.

81768913366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 834376683 (or 834376676 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 58.

The spelling of 81768913366 in words is "eighty-one billion, seven hundred sixty-eight million, nine hundred thirteen thousand, three hundred sixty-six".