159910981 has 2 divisors, whose sum is σ = 159910982. Its totient is φ = 159910980.

The previous prime is 159910979. The next prime is 159910991. The reversal of 159910981 is 189019951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111830625 + 48080356 = 10575^2 + 6934^2 .

It is a cyclic number.

It is not a de Polignac number, because 159910981 - 2¹ = 159910979 is a prime.

It is a super-2 number, since 2×159910981² = 51143043688764722, which contains 22 as substring.

Together with 159910979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159910991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79955490 + 79955491.

It is an arithmetic number, because the mean of its divisors is an integer number (79955491).

Almost surely, 2^159910981 is an apocalyptic number.

It is an amenable number.

159910981 is a deficient number, since it is larger than the sum of its proper divisors (1).

159910981 is an equidigital number, since it uses as much as digits as its factorization.

159910981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 29160, while the sum is 43.

The square root of 159910981 is about 12645.5913661639. The cubic root of 159910981 is about 542.7828234988.

The spelling of 159910981 in words is "one hundred fifty-nine million, nine hundred ten thousand, nine hundred eighty-one".