991493429791 has 2 divisors, whose sum is σ = 991493429792. Its totient is φ = 991493429790.

The previous prime is 991493429749. The next prime is 991493429803. The reversal of 991493429791 is 197924394199.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 991493429791 - 2¹⁵ = 991493397023 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (991493429191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 495746714895 + 495746714896.

It is an arithmetic number, because the mean of its divisors is an integer number (495746714896).

Almost surely, 2^991493429791 is an apocalyptic number.

991493429791 is a deficient number, since it is larger than the sum of its proper divisors (1).

991493429791 is an equidigital number, since it uses as much as digits as its factorization.

991493429791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39680928, while the sum is 67.

The spelling of 991493429791 in words is "nine hundred ninety-one billion, four hundred ninety-three million, four hundred twenty-nine thousand, seven hundred ninety-one".