204961 has 4 divisors (see below), whose sum is σ = 207172. Its totient is φ = 202752.

The previous prime is 204947. The next prime is 204973. The reversal of 204961 is 169402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 169402 = 2 ⋅84701.

It can be written as a sum of positive squares in 2 ways, for example, as 28561 + 176400 = 169^2 + 420^2 .

It is a cyclic number.

It is not a de Polignac number, because 204961 - 2¹³ = 196769 is a prime.

It is a Duffinian number.

204961 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (204931) 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, 960 + ... + 1153.

It is an arithmetic number, because the mean of its divisors is an integer number (51793).

2²⁰⁴⁹⁶¹ is an apocalyptic number.

It is an amenable number.

204961 is a deficient number, since it is larger than the sum of its proper divisors (2211).

204961 is an equidigital number, since it uses as much as digits as its factorization.

204961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2210.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 204961 is about 452.7261865631. The cubic root of 204961 is about 58.9599460020.

The spelling of 204961 in words is "two hundred four thousand, nine hundred sixty-one".