161872717 has 2 divisors, whose sum is σ = 161872718. Its totient is φ = 161872716.

The previous prime is 161872709. The next prime is 161872721. The reversal of 161872717 is 717278161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 88153321 + 73719396 = 9389^2 + 8586^2 .

It is a cyclic number.

It is not a de Polignac number, because 161872717 - 2³ = 161872709 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161872717.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161872757) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80936358 + 80936359.

It is an arithmetic number, because the mean of its divisors is an integer number (80936359).

Almost surely, 2^161872717 is an apocalyptic number.

It is an amenable number.

161872717 is a deficient number, since it is larger than the sum of its proper divisors (1).

161872717 is an equidigital number, since it uses as much as digits as its factorization.

161872717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32928, while the sum is 40.

The square root of 161872717 is about 12722.9209303524. The cubic root of 161872717 is about 544.9933697255.

The spelling of 161872717 in words is "one hundred sixty-one million, eight hundred seventy-two thousand, seven hundred seventeen".