161791386289 has 9 divisors (see below), whose sum is σ = 175199885409. Its totient is φ = 149341068240.

The previous prime is 161791386269. The next prime is 161791386301. The reversal of 161791386289 is 982683197161.

The square root of 161791386289 is 402233.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 53687207025 + 108104179264 = 231705^2 + 328792^2 .

It is not a de Polignac number, because 161791386289 - 2⁷ = 161791386161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161791386209) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5213559 + ... + 5244499.

Almost surely, 2^161791386289 is an apocalyptic number.

161791386289 is the 402233-rd square number.

161791386289 is the 201117-th centered octagonal number.

It is an amenable number.

161791386289 is a deficient number, since it is larger than the sum of its proper divisors (13408499120).

161791386289 is an frugal number, since it uses more digits than its factorization.

161791386289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61908 (or 30954 counting only the distinct ones).

The product of its digits is 7838208, while the sum is 61.

The spelling of 161791386289 in words is "one hundred sixty-one billion, seven hundred ninety-one million, three hundred eighty-six thousand, two hundred eighty-nine".