9999660321799 has 8 divisors (see below), whose sum is σ = 10665159401088. Its totient is φ = 9342748327680.

The previous prime is 9999660321793. The next prime is 9999660321809. The reversal of 9999660321799 is 9971230669999.

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

It is not a de Polignac number, because 9999660321799 - 2⁷ = 9999660321671 is a prime.

It is a super-2 number, since 2×9999660321799² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999660321793) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2146768887 + ... + 2146773544.

It is an arithmetic number, because the mean of its divisors is an integer number (1333144925136).

Almost surely, 2^{9999660321799} is an apocalyptic number.

9999660321799 is a deficient number, since it is larger than the sum of its proper divisors (665499079289).

9999660321799 is a wasteful number, since it uses less digits than its factorization.

9999660321799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4293542585.

The product of its (nonzero) digits is 803538792, while the sum is 79.

The spelling of 9999660321799 in words is "nine trillion, nine hundred ninety-nine billion, six hundred sixty million, three hundred twenty-one thousand, seven hundred ninety-nine".