205236121 has 4 divisors (see below), whose sum is σ = 217308852. Its totient is φ = 193163392.

The previous prime is 205235993. The next prime is 205236133. The reversal of 205236121 is 121632502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 109411600 + 95824521 = 10460^2 + 9789^2 .

It is a cyclic number.

It is not a de Polignac number, because 205236121 - 2⁷ = 205235993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205236092 and 205236101.

It is not an unprimeable number, because it can be changed into a prime (205230121) 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, 6036340 + ... + 6036373.

It is an arithmetic number, because the mean of its divisors is an integer number (54327213).

Almost surely, 2^205236121 is an apocalyptic number.

It is an amenable number.

205236121 is a deficient number, since it is larger than the sum of its proper divisors (12072731).

205236121 is a wasteful number, since it uses less digits than its factorization.

205236121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12072730.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 205236121 is about 14326.0643932659. The cubic root of 205236121 is about 589.8631502962.

Adding to 205236121 its reverse (121632502), we get a palindrome (326868623).

The spelling of 205236121 in words is "two hundred five million, two hundred thirty-six thousand, one hundred twenty-one".