205305242 has 4 divisors (see below), whose sum is σ = 307957866. Its totient is φ = 102652620.

The previous prime is 205305229. The next prime is 205305257. The reversal of 205305242 is 242503502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 242503502 = 2 ⋅121251751.

It can be written as a sum of positive squares in only one way, i.e., 106481761 + 98823481 = 10319^2 + 9941^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51326309 + ... + 51326312.

Almost surely, 2^205305242 is an apocalyptic number.

205305242 is a deficient number, since it is larger than the sum of its proper divisors (102652624).

205305242 is a wasteful number, since it uses less digits than its factorization.

205305242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102652623.

The product of its (nonzero) digits is 2400, while the sum is 23.

The square root of 205305242 is about 14328.4766112801. The cubic root of 205305242 is about 589.9293624137.

Adding to 205305242 its reverse (242503502), we get a palindrome (447808744).

The spelling of 205305242 in words is "two hundred five million, three hundred five thousand, two hundred forty-two".