205112321 has 4 divisors (see below), whose sum is σ = 214030272. Its totient is φ = 196194372.

The previous prime is 205112311. The next prime is 205112329. The reversal of 205112321 is 123211502.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 205112321 - 2²⁶ = 138003457 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 205112321.

It is not an unprimeable number, because it can be changed into a prime (205112329) 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, 4458941 + ... + 4458986.

It is an arithmetic number, because the mean of its divisors is an integer number (53507568).

Almost surely, 2^205112321 is an apocalyptic number.

It is an amenable number.

205112321 is a deficient number, since it is larger than the sum of its proper divisors (8917951).

205112321 is an equidigital number, since it uses as much as digits as its factorization.

205112321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8917950.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 205112321 is about 14321.7429456055. The cubic root of 205112321 is about 589.7445231174.

Adding to 205112321 its reverse (123211502), we get a palindrome (328323823).

The spelling of 205112321 in words is "two hundred five million, one hundred twelve thousand, three hundred twenty-one".