161705073607181 has 16 divisors (see below), whose sum is σ = 179315645804400. Its totient is φ = 144871045447680.

The previous prime is 161705073607169. The next prime is 161705073607211. The reversal of 161705073607181 is 181706370507161.

It can be written as a sum of positive squares in 8 ways, for example, as 19913326129225 + 141791747477956 = 4462435^2 + 11907634^2 .

It is a cyclic number.

It is not a de Polignac number, because 161705073607181 - 2¹⁸ = 161705073345037 is a prime.

It is a super-2 number, since 2×161705073607181² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161705073607481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 785872856 + ... + 786078593.

It is an arithmetic number, because the mean of its divisors is an integer number (11207227862775).

Almost surely, 2^{161705073607181} is an apocalyptic number.

It is an amenable number.

161705073607181 is a deficient number, since it is larger than the sum of its proper divisors (17610572197219).

161705073607181 is a wasteful number, since it uses less digits than its factorization.

161705073607181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1571951696.

The product of its (nonzero) digits is 1481760, while the sum is 53.

The spelling of 161705073607181 in words is "one hundred sixty-one trillion, seven hundred five billion, seventy-three million, six hundred seven thousand, one hundred eighty-one".