261422016487117 has 2 divisors, whose sum is σ = 261422016487118. Its totient is φ = 261422016487116.

The previous prime is 261422016487063. The next prime is 261422016487129. The reversal of 261422016487117 is 711784610224162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 150234882477156 + 111187134009961 = 12257034^2 + 10544531^2 .

It is a cyclic number.

It is not a de Polignac number, because 261422016487117 - 2¹⁹ = 261422015962829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261422016487717) 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, 130711008243558 + 130711008243559.

It is an arithmetic number, because the mean of its divisors is an integer number (130711008243559).

Almost surely, 2^{261422016487117} is an apocalyptic number.

It is an amenable number.

261422016487117 is a deficient number, since it is larger than the sum of its proper divisors (1).

261422016487117 is an equidigital number, since it uses as much as digits as its factorization.

261422016487117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1806336, while the sum is 52.

The spelling of 261422016487117 in words is "two hundred sixty-one trillion, four hundred twenty-two billion, sixteen million, four hundred eighty-seven thousand, one hundred seventeen".