161564266169 has 2 divisors, whose sum is σ = 161564266170. Its totient is φ = 161564266168.

The previous prime is 161564266117. The next prime is 161564266261. The reversal of 161564266169 is 961662465161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161234371600 + 329894569 = 401540^2 + 18163^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161564266169 is a prime.

It is a super-2 number, since 2×161564266169² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161564266169.

It is not a weakly prime, because it can be changed into another prime (161564266469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80782133084 + 80782133085.

It is an arithmetic number, because the mean of its divisors is an integer number (80782133085).

Almost surely, 2^161564266169 is an apocalyptic number.

It is an amenable number.

161564266169 is a deficient number, since it is larger than the sum of its proper divisors (1).

161564266169 is an equidigital number, since it uses as much as digits as its factorization.

161564266169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2799360, while the sum is 53.

The spelling of 161564266169 in words is "one hundred sixty-one billion, five hundred sixty-four million, two hundred sixty-six thousand, one hundred sixty-nine".