261165170281 has 2 divisors, whose sum is σ = 261165170282. Its totient is φ = 261165170280.

The previous prime is 261165170237. The next prime is 261165170293. The reversal of 261165170281 is 182071561162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 260900294656 + 264875625 = 510784^2 + 16275^2 .

It is a cyclic number.

It is not a de Polignac number, because 261165170281 - 2¹⁹ = 261164645993 is a prime.

It is a super-2 number, since 2×261165170281² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (261165170081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130582585140 + 130582585141.

It is an arithmetic number, because the mean of its divisors is an integer number (130582585141).

Almost surely, 2^261165170281 is an apocalyptic number.

It is an amenable number.

261165170281 is a deficient number, since it is larger than the sum of its proper divisors (1).

261165170281 is an equidigital number, since it uses as much as digits as its factorization.

261165170281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40320, while the sum is 40.

The spelling of 261165170281 in words is "two hundred sixty-one billion, one hundred sixty-five million, one hundred seventy thousand, two hundred eighty-one".