205465 has 16 divisors (see below), whose sum is σ = 277200. Its totient is φ = 145152.

The previous prime is 205463. The next prime is 205477. The reversal of 205465 is 564502.

205465 = 21² + 22² + ... + 85².

It can be written as a sum of positive squares in 8 ways, for example, as 4761 + 200704 = 69^2 + 448^2 .

It is a 4-Lehmer number, since φ(205465) divides (205465-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 205465 - 2¹ = 205463 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205463) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1831 + ... + 1939.

It is an arithmetic number, because the mean of its divisors is an integer number (17325).

2²⁰⁵⁴⁶⁵ is an apocalyptic number.

It is an amenable number.

205465 is a deficient number, since it is larger than the sum of its proper divisors (71735).

205465 is a wasteful number, since it uses less digits than its factorization.

205465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 205465 is about 453.2824726371. The cubic root of 205465 is about 59.0082340323.

Adding to 205465 its reverse (564502), we get a palindrome (769967).

The spelling of 205465 in words is "two hundred five thousand, four hundred sixty-five".