991330001321331 has 32 divisors (see below), whose sum is σ = 1535422443563008. Its totient is φ = 557165887770240.

The previous prime is 991330001321311. The next prime is 991330001321447. The reversal of 991330001321331 is 133123100033199.

It is not a de Polignac number, because 991330001321331 - 2⁶ = 991330001321267 is a prime.

It is a super-2 number, since 2×991330001321331² (a number of 31 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 991330001321331.

It is not an unprimeable number, because it can be changed into a prime (991330001321311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17346945 + ... + 47786781.

It is an arithmetic number, because the mean of its divisors is an integer number (47981951361344).

Almost surely, 2^{991330001321331} is an apocalyptic number.

991330001321331 is a deficient number, since it is larger than the sum of its proper divisors (544092442241677).

991330001321331 is a wasteful number, since it uses less digits than its factorization.

991330001321331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30465331.

The product of its (nonzero) digits is 39366, while the sum is 39.

The spelling of 991330001321331 in words is "nine hundred ninety-one trillion, three hundred thirty billion, one million, three hundred twenty-one thousand, three hundred thirty-one".