65161 has 4 divisors (see below), whose sum is σ = 69012. Its totient is φ = 61312.

The previous prime is 65147. The next prime is 65167. The reversal of 65161 is 16156.

65161 = 180² + 181².

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 32400 + 32761 = 180^2 + 181^2 .

It is a cyclic number.

It is not a de Polignac number, because 65161 - 2⁵ = 65129 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65167) 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, 1900 + ... + 1933.

It is an arithmetic number, because the mean of its divisors is an integer number (17253).

2⁶⁵¹⁶¹ is an apocalyptic number.

65161 is the 181-st centered square number.

It is an amenable number.

65161 is a deficient number, since it is larger than the sum of its proper divisors (3851).

65161 is a wasteful number, since it uses less digits than its factorization.

65161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3850.

The product of its digits is 180, while the sum is 19.

The square root of 65161 is about 255.2665273787. The cubic root of 65161 is about 40.2404269763.

Adding to 65161 its product of digits (180), we get a triangular number (65341 = T₃₆₁).

The spelling of 65161 in words is "sixty-five thousand, one hundred sixty-one".