205423 has 2 divisors, whose sum is σ = 205424. Its totient is φ = 205422.

The previous prime is 205421. The next prime is 205427. The reversal of 205423 is 324502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 205423 - 2¹ = 205421 is a prime.

Together with 205421, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 205397 and 205406.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102711 + 102712.

It is an arithmetic number, because the mean of its divisors is an integer number (102712).

2²⁰⁵⁴²³ is an apocalyptic number.

205423 is a deficient number, since it is larger than the sum of its proper divisors (1).

205423 is an equidigital number, since it uses as much as digits as its factorization.

205423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 16.

The square root of 205423 is about 453.2361415421. The cubic root of 205423 is about 59.0042130478.

Adding to 205423 its reverse (324502), we get a palindrome (529925).

The spelling of 205423 in words is "two hundred five thousand, four hundred twenty-three".