161564266117 has 2 divisors, whose sum is σ = 161564266118. Its totient is φ = 161564266116.

The previous prime is 161564266093. The next prime is 161564266169. The reversal of 161564266117 is 711662465161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150333777441 + 11230488676 = 387729^2 + 105974^2 .

It is a cyclic number.

It is not a de Polignac number, because 161564266117 - 2¹⁵ = 161564233349 is a prime.

It is a super-2 number, since 2×161564266117² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161564269117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80782133058 + 80782133059.

It is an arithmetic number, because the mean of its divisors is an integer number (80782133059).

Almost surely, 2^161564266117 is an apocalyptic number.

It is an amenable number.

161564266117 is a deficient number, since it is larger than the sum of its proper divisors (1).

161564266117 is an equidigital number, since it uses as much as digits as its factorization.

161564266117 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 46.

The spelling of 161564266117 in words is "one hundred sixty-one billion, five hundred sixty-four million, two hundred sixty-six thousand, one hundred seventeen".