81693917983 has 8 divisors (see below), whose sum is σ = 82280119680. Its totient is φ = 81109449120.

The previous prime is 81693917969. The next prime is 81693918011. The reversal of 81693917983 is 38971939618.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81693917983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81693914983) by changing a digit.

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, 338508 + ... + 527233.

It is an arithmetic number, because the mean of its divisors is an integer number (10285014960).

Almost surely, 2^81693917983 is an apocalyptic number.

81693917983 is a deficient number, since it is larger than the sum of its proper divisors (586201697).

81693917983 is a wasteful number, since it uses less digits than its factorization.

81693917983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 866417.

The product of its digits is 17635968, while the sum is 64.

The spelling of 81693917983 in words is "eighty-one billion, six hundred ninety-three million, nine hundred seventeen thousand, nine hundred eighty-three".