161728617 has 16 divisors (see below), whose sum is σ = 228833280. Its totient is φ = 101380752.

The previous prime is 161728613. The next prime is 161728631. The reversal of 161728617 is 716827161.

It is not a de Polignac number, because 161728617 - 2² = 161728613 is a prime.

It is a super-3 number, since 3×161728617³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not an unprimeable number, because it can be changed into a prime (161728613) 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 15 ways as a sum of consecutive naturals, for example, 15793 + ... + 23934.

It is an arithmetic number, because the mean of its divisors is an integer number (14302080).

Almost surely, 2^161728617 is an apocalyptic number.

It is an amenable number.

161728617 is a deficient number, since it is larger than the sum of its proper divisors (67104663).

161728617 is a wasteful number, since it uses less digits than its factorization.

161728617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39812.

The product of its digits is 28224, while the sum is 39.

The square root of 161728617 is about 12717.2566617176. The cubic root of 161728617 is about 544.8316029966.

The spelling of 161728617 in words is "one hundred sixty-one million, seven hundred twenty-eight thousand, six hundred seventeen".