210161 has 6 divisors (see below), whose sum is σ = 244530. Its totient is φ = 180096.

The previous prime is 210157. The next prime is 210169. The reversal of 210161 is 161012.

It can be written as a sum of positive squares in only one way, i.e., 207025 + 3136 = 455^2 + 56^2 .

It is not a de Polignac number, because 210161 - 2² = 210157 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 210161.

It is not an unprimeable number, because it can be changed into a prime (210169) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2096 + ... + 2193.

It is an arithmetic number, because the mean of its divisors is an integer number (40755).

2²¹⁰¹⁶¹ is an apocalyptic number.

It is an amenable number.

210161 is a deficient number, since it is larger than the sum of its proper divisors (34369).

210161 is an equidigital number, since it uses as much as digits as its factorization.

210161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4303 (or 4296 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 210161 is about 458.4332012409. The cubic root of 210161 is about 59.4544056702.

Adding to 210161 its reverse (161012), we get a palindrome (371173).

The spelling of 210161 in words is "two hundred ten thousand, one hundred sixty-one".