161665706 has 16 divisors (see below), whose sum is σ = 248822280. Its totient is φ = 78731520.

The previous prime is 161665697. The next prime is 161665711. The reversal of 161665706 is 607566161.

It can be written as a sum of positive squares in 4 ways, for example, as 156025081 + 5640625 = 12491^2 + 2375^2 .

It is a super-2 number, since 2×161665706² = 52271600992956872, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 161665706.

It is an unprimeable number.

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, 65120 + ... + 67556.

Almost surely, 2^161665706 is an apocalyptic number.

161665706 is a deficient number, since it is larger than the sum of its proper divisors (87156574).

161665706 is a wasteful number, since it uses less digits than its factorization.

161665706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3289.

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 161665706 is about 12714.7829710145. The cubic root of 161665706 is about 544.7609489447.

The spelling of 161665706 in words is "one hundred sixty-one million, six hundred sixty-five thousand, seven hundred six".