81788641336 has 32 divisors (see below), whose sum is σ = 157120203600. Its totient is φ = 39898543360.

The previous prime is 81788641321. The next prime is 81788641343. The reversal of 81788641336 is 63314688718.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 462925 + ... + 614716.

Almost surely, 2^81788641336 is an apocalyptic number.

It is an amenable number.

81788641336 is a deficient number, since it is larger than the sum of its proper divisors (75331562264).

81788641336 is a wasteful number, since it uses less digits than its factorization.

81788641336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077879 (or 1077875 counting only the distinct ones).

The product of its digits is 4644864, while the sum is 55.

The spelling of 81788641336 in words is "eighty-one billion, seven hundred eighty-eight million, six hundred forty-one thousand, three hundred thirty-six".