261386171 has 2 divisors, whose sum is σ = 261386172. Its totient is φ = 261386170.

The previous prime is 261386161. The next prime is 261386183. The reversal of 261386171 is 171683162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261386171 - 2²² = 257191867 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (261386161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130693085 + 130693086.

It is an arithmetic number, because the mean of its divisors is an integer number (130693086).

Almost surely, 2^261386171 is an apocalyptic number.

261386171 is a deficient number, since it is larger than the sum of its proper divisors (1).

261386171 is an equidigital number, since it uses as much as digits as its factorization.

261386171 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 35.

The square root of 261386171 is about 16167.4416961992. The cubic root of 261386171 is about 639.3826819324.

The spelling of 261386171 in words is "two hundred sixty-one million, three hundred eighty-six thousand, one hundred seventy-one".