161009005 has 4 divisors (see below), whose sum is σ = 193210812. Its totient is φ = 128807200.

The previous prime is 161008979. The next prime is 161009029. The reversal of 161009005 is 500900161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 500900161 = 3319 ⋅150919.

It can be written as a sum of positive squares in 2 ways, for example, as 28965924 + 132043081 = 5382^2 + 11491^2 .

It is not a de Polignac number, because 161009005 - 2⁷ = 161008877 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16100896 + ... + 16100905.

It is an arithmetic number, because the mean of its divisors is an integer number (48302703).

Almost surely, 2^161009005 is an apocalyptic number.

It is an amenable number.

161009005 is a deficient number, since it is larger than the sum of its proper divisors (32201807).

161009005 is an equidigital number, since it uses as much as digits as its factorization.

161009005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32201806.

The product of its (nonzero) digits is 270, while the sum is 22.

The square root of 161009005 is about 12688.9323821983. The cubic root of 161009005 is about 544.0223248570.

Adding to 161009005 its reverse (500900161), we get a palindrome (661909166).

The spelling of 161009005 in words is "one hundred sixty-one million, nine thousand, five".