204145 has 4 divisors (see below), whose sum is σ = 244980. Its totient is φ = 163312.

The previous prime is 204143. The next prime is 204151. The reversal of 204145 is 541402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 541402 = 2 ⋅270701.

It can be written as a sum of positive squares in 2 ways, for example, as 159201 + 44944 = 399^2 + 212^2 .

It is a cyclic number.

It is not a de Polignac number, because 204145 - 2¹ = 204143 is a prime.

It is a super-3 number, since 3×204145³ = 25523339491045875, which contains 333 as substring.

204145 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (204143) 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, 20410 + ... + 20419.

It is an arithmetic number, because the mean of its divisors is an integer number (61245).

2²⁰⁴¹⁴⁵ is an apocalyptic number.

It is an amenable number.

204145 is a deficient number, since it is larger than the sum of its proper divisors (40835).

204145 is an equidigital number, since it uses as much as digits as its factorization.

204145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40834.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 204145 is about 451.8240808102. The cubic root of 204145 is about 58.8815972671.

Adding to 204145 its reverse (541402), we get a palindrome (745547).

The spelling of 204145 in words is "two hundred four thousand, one hundred forty-five".