204121121 has 4 divisors (see below), whose sum is σ = 205249044. Its totient is φ = 202993200.

The previous prime is 204121109. The next prime is 204121133. The reversal of 204121121 is 121121402.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (204121109) and next prime (204121133).

It can be written as a sum of positive squares in 2 ways, for example, as 34105600 + 170015521 = 5840^2 + 13039^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204121121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204121096 and 204121105.

It is not an unprimeable number, because it can be changed into a prime (204121721) 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, 563690 + ... + 564051.

It is an arithmetic number, because the mean of its divisors is an integer number (51312261).

Almost surely, 2^204121121 is an apocalyptic number.

It is an amenable number.

204121121 is a deficient number, since it is larger than the sum of its proper divisors (1127923).

204121121 is a wasteful number, since it uses less digits than its factorization.

204121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1127922.

The product of its (nonzero) digits is 32, while the sum is 14.

The square root of 204121121 is about 14287.0963110074. The cubic root of 204121121 is about 588.7930136877.

Adding to 204121121 its reverse (121121402), we get a palindrome (325242523).

The spelling of 204121121 in words is "two hundred four million, one hundred twenty-one thousand, one hundred twenty-one".