165781241 has 2 divisors, whose sum is σ = 165781242. Its totient is φ = 165781240.

The previous prime is 165781181. The next prime is 165781271. The reversal of 165781241 is 142187561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129299641 + 36481600 = 11371^2 + 6040^2 .

It is a cyclic number.

It is not a de Polignac number, because 165781241 - 2⁶ = 165781177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (165781271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82890620 + 82890621.

It is an arithmetic number, because the mean of its divisors is an integer number (82890621).

Almost surely, 2^165781241 is an apocalyptic number.

It is an amenable number.

165781241 is a deficient number, since it is larger than the sum of its proper divisors (1).

165781241 is an equidigital number, since it uses as much as digits as its factorization.

165781241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13440, while the sum is 35.

The square root of 165781241 is about 12875.6064323200. The cubic root of 165781241 is about 549.3449402321.

The spelling of 165781241 in words is "one hundred sixty-five million, seven hundred eighty-one thousand, two hundred forty-one".