161606055565589 has 2 divisors, whose sum is σ = 161606055565590. Its totient is φ = 161606055565588.

The previous prime is 161606055565481. The next prime is 161606055565597. The reversal of 161606055565589 is 985565550606161.

161606055565589 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., 116930333245489 + 44675722320100 = 10813433^2 + 6683990^2 .

It is a cyclic number.

It is not a de Polignac number, because 161606055565589 - 2²⁸ = 161605787130133 is a prime.

It is a super-2 number, since 2×161606055565589² (a number of 29 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161606055561589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80803027782794 + 80803027782795.

It is an arithmetic number, because the mean of its divisors is an integer number (80803027782795).

Almost surely, 2^{161606055565589} is an apocalyptic number.

It is an amenable number.

161606055565589 is a deficient number, since it is larger than the sum of its proper divisors (1).

161606055565589 is an equidigital number, since it uses as much as digits as its factorization.

161606055565589 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 291600000, while the sum is 68.

The spelling of 161606055565589 in words is "one hundred sixty-one trillion, six hundred six billion, fifty-five million, five hundred sixty-five thousand, five hundred eighty-nine".