205242321 has 4 divisors (see below), whose sum is σ = 273656432. Its totient is φ = 136828212.

The previous prime is 205242299. The next prime is 205242329. The reversal of 205242321 is 123242502.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 205242321 - 2²² = 201048017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205242329) 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, 34207051 + ... + 34207056.

It is an arithmetic number, because the mean of its divisors is an integer number (68414108).

Almost surely, 2^205242321 is an apocalyptic number.

It is an amenable number.

205242321 is a deficient number, since it is larger than the sum of its proper divisors (68414111).

205242321 is an equidigital number, since it uses as much as digits as its factorization.

205242321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68414110.

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 205242321 is about 14326.2807804398. The cubic root of 205242321 is about 589.8690899828.

Adding to 205242321 its reverse (123242502), we get a palindrome (328484823).

The spelling of 205242321 in words is "two hundred five million, two hundred forty-two thousand, three hundred twenty-one".