159999221 has 2 divisors, whose sum is σ = 159999222. Its totient is φ = 159999220.

The previous prime is 159999187. The next prime is 159999227. The reversal of 159999221 is 122999951.

159999221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 128482225 + 31516996 = 11335^2 + 5614^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-159999221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159999227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79999610 + 79999611.

It is an arithmetic number, because the mean of its divisors is an integer number (79999611).

Almost surely, 2^159999221 is an apocalyptic number.

It is an amenable number.

159999221 is a deficient number, since it is larger than the sum of its proper divisors (1).

159999221 is an equidigital number, since it uses as much as digits as its factorization.

159999221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 131220, while the sum is 47.

The square root of 159999221 is about 12649.0798479573. The cubic root of 159999221 is about 542.8826422628.

The spelling of 159999221 in words is "one hundred fifty-nine million, nine hundred ninety-nine thousand, two hundred twenty-one".