159871661 has 2 divisors, whose sum is σ = 159871662. Its totient is φ = 159871660.

The previous prime is 159871639. The next prime is 159871697. The reversal of 159871661 is 166178951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82537225 + 77334436 = 9085^2 + 8794^2 .

It is a cyclic number.

It is not a de Polignac number, because 159871661 - 2¹⁰ = 159870637 is a prime.

It is a super-3 number, since 3×159871661³ (a number of 26 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159871601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79935830 + 79935831.

It is an arithmetic number, because the mean of its divisors is an integer number (79935831).

Almost surely, 2^159871661 is an apocalyptic number.

It is an amenable number.

159871661 is a deficient number, since it is larger than the sum of its proper divisors (1).

159871661 is an equidigital number, since it uses as much as digits as its factorization.

159871661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 44.

The square root of 159871661 is about 12644.0365785615. The cubic root of 159871661 is about 542.7383321408.

The spelling of 159871661 in words is "one hundred fifty-nine million, eight hundred seventy-one thousand, six hundred sixty-one".