161920004489 has 2 divisors, whose sum is σ = 161920004490. Its totient is φ = 161920004488.

The previous prime is 161920004473. The next prime is 161920004593. The reversal of 161920004489 is 984400029161.

161920004489 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 158694673225 + 3225331264 = 398365^2 + 56792^2 .

It is a cyclic number.

It is not a de Polignac number, because 161920004489 - 2⁴ = 161920004473 is a prime.

It is a super-2 number, since 2×161920004489² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161920004429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80960002244 + 80960002245.

It is an arithmetic number, because the mean of its divisors is an integer number (80960002245).

Almost surely, 2^161920004489 is an apocalyptic number.

It is an amenable number.

161920004489 is a deficient number, since it is larger than the sum of its proper divisors (1).

161920004489 is an equidigital number, since it uses as much as digits as its factorization.

161920004489 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 44.

The spelling of 161920004489 in words is "one hundred sixty-one billion, nine hundred twenty million, four thousand, four hundred eighty-nine".