161505161 has 8 divisors (see below), whose sum is σ = 163630848. Its totient is φ = 159390000.

The previous prime is 161505139. The next prime is 161505163.

161505161 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 161505161 - 2²⁶ = 94396297 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161505161.

It is not an unprimeable number, because it can be changed into a prime (161505163) 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, 31016 + ... + 35846.

It is an arithmetic number, because the mean of its divisors is an integer number (20453856).

Almost surely, 2^161505161 is an apocalyptic number.

It is an amenable number.

161505161 is a deficient number, since it is larger than the sum of its proper divisors (2125687).

161505161 is a wasteful number, since it uses less digits than its factorization.

161505161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5263.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 161505161 is about 12708.4680823457. The cubic root of 161505161 is about 544.5805610412.

The spelling of 161505161 in words is "one hundred sixty-one million, five hundred five thousand, one hundred sixty-one".