991329203647 has 8 divisors (see below), whose sum is σ = 1033587878400. Its totient is φ = 949608856224.

The previous prime is 991329203633. The next prime is 991329203653. The reversal of 991329203647 is 746302923199.

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-991329203647 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 (991329203677) 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, 134578072 + ... + 134585437.

It is an arithmetic number, because the mean of its divisors is an integer number (129198484800).

Almost surely, 2^991329203647 is an apocalyptic number.

991329203647 is a deficient number, since it is larger than the sum of its proper divisors (42258674753).

991329203647 is a wasteful number, since it uses less digits than its factorization.

991329203647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269163665.

The product of its (nonzero) digits is 4408992, while the sum is 55.

The spelling of 991329203647 in words is "nine hundred ninety-one billion, three hundred twenty-nine million, two hundred three thousand, six hundred forty-seven".