9817979919805 has 8 divisors (see below), whose sum is σ = 11802727748952. Its totient is φ = 7840282705728.

The previous prime is 9817979919773. The next prime is 9817979919823. The reversal of 9817979919805 is 5089199797189.

It can be written as a sum of positive squares in 4 ways, for example, as 380040192676 + 9437939727129 = 616474^2 + 3072123^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 9817979919805 - 2⁵ = 9817979919773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1762650702 + ... + 1762656271.

It is an arithmetic number, because the mean of its divisors is an integer number (1475340968619).

Almost surely, 2^{9817979919805} is an apocalyptic number.

It is an amenable number.

9817979919805 is a deficient number, since it is larger than the sum of its proper divisors (1984747829147).

9817979919805 is a wasteful number, since it uses less digits than its factorization.

9817979919805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3525307535.

The product of its (nonzero) digits is 925888320, while the sum is 82.

The spelling of 9817979919805 in words is "nine trillion, eight hundred seventeen billion, nine hundred seventy-nine million, nine hundred nineteen thousand, eight hundred five".