159881021 has 2 divisors, whose sum is σ = 159881022. Its totient is φ = 159881020.

The previous prime is 159880999. The next prime is 159881083. The reversal of 159881021 is 120188951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 114789796 + 45091225 = 10714^2 + 6715^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-159881021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159881621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79940510 + 79940511.

It is an arithmetic number, because the mean of its divisors is an integer number (79940511).

Almost surely, 2^159881021 is an apocalyptic number.

It is an amenable number.

159881021 is a deficient number, since it is larger than the sum of its proper divisors (1).

159881021 is an equidigital number, since it uses as much as digits as its factorization.

159881021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 35.

The square root of 159881021 is about 12644.4067081062. The cubic root of 159881021 is about 542.7489238276.

The spelling of 159881021 in words is "one hundred fifty-nine million, eight hundred eighty-one thousand, twenty-one".