159404981 has 2 divisors, whose sum is σ = 159404982. Its totient is φ = 159404980.

The previous prime is 159404969. The next prime is 159405013. The reversal of 159404981 is 189404951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157904356 + 1500625 = 12566^2 + 1225^2 .

It is a cyclic number.

It is not a de Polignac number, because 159404981 - 2²⁶ = 92296117 is a prime.

It is a super-2 number, since 2×159404981² = 50819895935220722, which contains 22 as substring.

It is a Chen prime.

It is equal to p_8942918 and since 159404981 and 8942918 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159404941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79702490 + 79702491.

It is an arithmetic number, because the mean of its divisors is an integer number (79702491).

Almost surely, 2^159404981 is an apocalyptic number.

It is an amenable number.

159404981 is a deficient number, since it is larger than the sum of its proper divisors (1).

159404981 is an equidigital number, since it uses as much as digits as its factorization.

159404981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 41.

The square root of 159404981 is about 12625.5685416539. The cubic root of 159404981 is about 542.2097165045.

The spelling of 159404981 in words is "one hundred fifty-nine million, four hundred four thousand, nine hundred eighty-one".