159716621 has 2 divisors, whose sum is σ = 159716622. Its totient is φ = 159716620.

The previous prime is 159716569. The next prime is 159716639. The reversal of 159716621 is 126617951.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90992521 + 68724100 = 9539^2 + 8290^2 .

It is an emirp because it is prime and its reverse (126617951) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 159716621 - 2²² = 155522317 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is equal to p_8959340 and since 159716621 and 8959340 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 (159716321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 79858310 + 79858311.

It is an arithmetic number, because the mean of its divisors is an integer number (79858311).

Almost surely, 2^159716621 is an apocalyptic number.

It is an amenable number.

159716621 is a deficient number, since it is larger than the sum of its proper divisors (1).

159716621 is an equidigital number, since it uses as much as digits as its factorization.

159716621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 38.

The square root of 159716621 is about 12637.9041379495. The cubic root of 159716621 is about 542.5628301868.

The spelling of 159716621 in words is "one hundred fifty-nine million, seven hundred sixteen thousand, six hundred twenty-one".