205366243 has 4 divisors (see below), whose sum is σ = 210916720. Its totient is φ = 199815768.

The previous prime is 205366201. The next prime is 205366261. The reversal of 205366243 is 342663502.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 342663502 = 2 ⋅171331751.

It is a cyclic number.

It is not a de Polignac number, because 205366243 - 2²⁵ = 171811811 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205366543) 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, 2775183 + ... + 2775256.

It is an arithmetic number, because the mean of its divisors is an integer number (52729180).

Almost surely, 2^205366243 is an apocalyptic number.

205366243 is a deficient number, since it is larger than the sum of its proper divisors (5550477).

205366243 is an equidigital number, since it uses as much as digits as its factorization.

205366243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5550476.

The product of its (nonzero) digits is 25920, while the sum is 31.

The square root of 205366243 is about 14330.6051163236. The cubic root of 205366243 is about 589.9877839087.

The spelling of 205366243 in words is "two hundred five million, three hundred sixty-six thousand, two hundred forty-three".