159870721 has 2 divisors, whose sum is σ = 159870722. Its totient is φ = 159870720.

The previous prime is 159870719. The next prime is 159870743. The reversal of 159870721 is 127078951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137733696 + 22137025 = 11736^2 + 4705^2 .

It is a cyclic number.

It is not a de Polignac number, because 159870721 - 2¹ = 159870719 is a prime.

Together with 159870719, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (159870701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79935360 + 79935361.

It is an arithmetic number, because the mean of its divisors is an integer number (79935361).

Almost surely, 2^159870721 is an apocalyptic number.

It is an amenable number.

159870721 is a deficient number, since it is larger than the sum of its proper divisors (1).

159870721 is an equidigital number, since it uses as much as digits as its factorization.

159870721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35280, while the sum is 40.

The square root of 159870721 is about 12643.9994068333. Note that the first 3 decimals coincide. The cubic root of 159870721 is about 542.7372684230.

The spelling of 159870721 in words is "one hundred fifty-nine million, eight hundred seventy thousand, seven hundred twenty-one".