159509816621 has 2 divisors, whose sum is σ = 159509816622. Its totient is φ = 159509816620.

The previous prime is 159509816573. The next prime is 159509816717. The reversal of 159509816621 is 126618905951.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 148371336100 + 11138480521 = 385190^2 + 105539^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-159509816621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (159509819621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79754908310 + 79754908311.

It is an arithmetic number, because the mean of its divisors is an integer number (79754908311).

Almost surely, 2^159509816621 is an apocalyptic number.

It is an amenable number.

159509816621 is a deficient number, since it is larger than the sum of its proper divisors (1).

159509816621 is an equidigital number, since it uses as much as digits as its factorization.

159509816621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1166400, while the sum is 53.

The spelling of 159509816621 in words is "one hundred fifty-nine billion, five hundred nine million, eight hundred sixteen thousand, six hundred twenty-one".