161909161 has 8 divisors (see below), whose sum is σ = 163888704. Its totient is φ = 159937200.

The previous prime is 161909141. The next prime is 161909177.

161909161 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161909161 - 2⁵ = 161909129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161909141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49210 + ... + 52396.

It is an arithmetic number, because the mean of its divisors is an integer number (20486088).

Almost surely, 2^161909161 is an apocalyptic number.

It is an amenable number.

161909161 is a deficient number, since it is larger than the sum of its proper divisors (1979543).

161909161 is a wasteful number, since it uses less digits than its factorization.

161909161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3791.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 161909161 is about 12724.3530680345. The cubic root of 161909161 is about 545.0342665658.

The spelling of 161909161 in words is "one hundred sixty-one million, nine hundred nine thousand, one hundred sixty-one".