791421121124209 has 2 divisors, whose sum is σ = 791421121124210. Its totient is φ = 791421121124208.

The previous prime is 791421121124191. The next prime is 791421121124251. The reversal of 791421121124209 is 902421121124197.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 425136068093584 + 366285053030625 = 20618828^2 + 19138575^2 .

It is a cyclic number.

It is not a de Polignac number, because 791421121124209 - 2²⁷ = 791420986906481 is a prime.

It is a super-2 number, since 2×791421121124209² (a number of 31 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (791421121121209) 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 as a sum of consecutive naturals, namely, 395710560562104 + 395710560562105.

It is an arithmetic number, because the mean of its divisors is an integer number (395710560562105).

Almost surely, 2^{791421121124209} is an apocalyptic number.

It is an amenable number.

791421121124209 is a deficient number, since it is larger than the sum of its proper divisors (1).

791421121124209 is an equidigital number, since it uses as much as digits as its factorization.

791421121124209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 46.

The spelling of 791421121124209 in words is "seven hundred ninety-one trillion, four hundred twenty-one billion, one hundred twenty-one million, one hundred twenty-four thousand, two hundred nine".