243117731325691 has 2 divisors, whose sum is σ = 243117731325692. Its totient is φ = 243117731325690.

The previous prime is 243117731325643. The next prime is 243117731325773. The reversal of 243117731325691 is 196523137711342.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 243117731325691 - 2²³ = 243117722937083 is a prime.

It is not a weakly prime, because it can be changed into another prime (243117731325631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 121558865662845 + 121558865662846.

It is an arithmetic number, because the mean of its divisors is an integer number (121558865662846).

Almost surely, 2^{243117731325691} is an apocalyptic number.

243117731325691 is a deficient number, since it is larger than the sum of its proper divisors (1).

243117731325691 is an equidigital number, since it uses as much as digits as its factorization.

243117731325691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5715360, while the sum is 55.

The spelling of 243117731325691 in words is "two hundred forty-three trillion, one hundred seventeen billion, seven hundred thirty-one million, three hundred twenty-five thousand, six hundred ninety-one".