991321113033101 has 4 divisors (see below), whose sum is σ = 991321773180000. Its totient is φ = 991320452886204.

The previous prime is 991321113033089. The next prime is 991321113033137. The reversal of 991321113033101 is 101330311123199.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-991321113033101 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 (991321113033001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 327815801 + ... + 330825998.

It is an arithmetic number, because the mean of its divisors is an integer number (247830443295000).

Almost surely, 2^{991321113033101} is an apocalyptic number.

It is an amenable number.

991321113033101 is a deficient number, since it is larger than the sum of its proper divisors (660146899).

991321113033101 is a wasteful number, since it uses less digits than its factorization.

991321113033101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660146898.

The product of its (nonzero) digits is 13122, while the sum is 38.

The spelling of 991321113033101 in words is "nine hundred ninety-one trillion, three hundred twenty-one billion, one hundred thirteen million, thirty-three thousand, one hundred one".