161761 has 2 divisors, whose sum is σ = 161762. Its totient is φ = 161760.

The previous prime is 161753. The next prime is 161771. The reversal of 161761 is 167161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136161 + 25600 = 369^2 + 160^2 .

It is a cyclic number.

It is not a de Polignac number, because 161761 - 2³ = 161753 is a prime.

It is a super-2 number, since 2×161761² = 52333242242, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80880 + 80881.

It is an arithmetic number, because the mean of its divisors is an integer number (80881).

2¹⁶¹⁷⁶¹ is an apocalyptic number.

It is an amenable number.

161761 is a deficient number, since it is larger than the sum of its proper divisors (1).

161761 is an equidigital number, since it uses as much as digits as its factorization.

161761 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252, while the sum is 22.

The square root of 161761 is about 402.1952262273. The cubic root of 161761 is about 54.4867964536.

The spelling of 161761 in words is "one hundred sixty-one thousand, seven hundred sixty-one".