161966317 has 4 divisors (see below), whose sum is σ = 170490880. Its totient is φ = 153441756.

The previous prime is 161966309. The next prime is 161966333. The reversal of 161966317 is 713669161.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 161966317 - 2³ = 161966309 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 161966317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161966347) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4262253 + ... + 4262290.

It is an arithmetic number, because the mean of its divisors is an integer number (42622720).

Almost surely, 2^161966317 is an apocalyptic number.

It is an amenable number.

161966317 is a deficient number, since it is larger than the sum of its proper divisors (8524563).

161966317 is an equidigital number, since it uses as much as digits as its factorization.

161966317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8524562.

The product of its digits is 40824, while the sum is 40.

The square root of 161966317 is about 12726.5987993651. The cubic root of 161966317 is about 545.0983937043.

The spelling of 161966317 in words is "one hundred sixty-one million, nine hundred sixty-six thousand, three hundred seventeen".