161543317 has 4 divisors (see below), whose sum is σ = 173969740. Its totient is φ = 149116896.

The previous prime is 161543293. The next prime is 161543359. The reversal of 161543317 is 713345161.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 110649361 + 50893956 = 10519^2 + 7134^2 .

It is a cyclic number.

It is not a de Polignac number, because 161543317 - 2²⁷ = 27325589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161543017) 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 3 ways as a sum of consecutive naturals, for example, 6213192 + ... + 6213217.

It is an arithmetic number, because the mean of its divisors is an integer number (43492435).

Almost surely, 2^161543317 is an apocalyptic number.

It is an amenable number.

161543317 is a deficient number, since it is larger than the sum of its proper divisors (12426423).

161543317 is a wasteful number, since it uses less digits than its factorization.

161543317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12426422.

The product of its digits is 7560, while the sum is 31.

The square root of 161543317 is about 12709.9691974450. The cubic root of 161543317 is about 544.6234438395.

Adding to 161543317 its reverse (713345161), we get a palindrome (874888478).

The spelling of 161543317 in words is "one hundred sixty-one million, five hundred forty-three thousand, three hundred seventeen".