991012310329 has 2 divisors, whose sum is σ = 991012310330. Its totient is φ = 991012310328.

The previous prime is 991012310297. The next prime is 991012310347. The reversal of 991012310329 is 923013210199.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 956431188729 + 34581121600 = 977973^2 + 185960^2 .

It is a cyclic number.

It is not a de Polignac number, because 991012310329 - 2⁵ = 991012310297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 991012310291 and 991012310300.

It is not a weakly prime, because it can be changed into another prime (991012310359) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495506155164 + 495506155165.

It is an arithmetic number, because the mean of its divisors is an integer number (495506155165).

Almost surely, 2^991012310329 is an apocalyptic number.

It is an amenable number.

991012310329 is a deficient number, since it is larger than the sum of its proper divisors (1).

991012310329 is an equidigital number, since it uses as much as digits as its factorization.

991012310329 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26244, while the sum is 40.

The spelling of 991012310329 in words is "nine hundred ninety-one billion, twelve million, three hundred ten thousand, three hundred twenty-nine".