991213310113 has 16 divisors (see below), whose sum is σ = 1093629740112. Its totient is φ = 892540800000.

The previous prime is 991213310047. The next prime is 991213310141. The reversal of 991213310113 is 311013312199.

It can be written as a sum of positive squares in 8 ways, for example, as 357379187344 + 633834122769 = 597812^2 + 796137^2 .

It is a cyclic number.

It is not a de Polignac number, because 991213310113 - 2²⁵ = 991179755681 is a prime.

It is a super-2 number, since 2×991213310113² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (991213310183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4421653 + ... + 4640413.

It is an arithmetic number, because the mean of its divisors is an integer number (68351858757).

Almost surely, 2^991213310113 is an apocalyptic number.

It is an amenable number.

991213310113 is a deficient number, since it is larger than the sum of its proper divisors (102416429999).

991213310113 is a wasteful number, since it uses less digits than its factorization.

991213310113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227316.

The product of its (nonzero) digits is 4374, while the sum is 34.

The spelling of 991213310113 in words is "nine hundred ninety-one billion, two hundred thirteen million, three hundred ten thousand, one hundred thirteen".