205104121 has 4 divisors (see below), whose sum is σ = 205654372. Its totient is φ = 204553872.

The previous prime is 205104113. The next prime is 205104157. The reversal of 205104121 is 121401502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121401502 = 2 ⋅60700751.

It can be written as a sum of positive squares in 2 ways, for example, as 144264121 + 60840000 = 12011^2 + 7800^2 .

It is a cyclic number.

It is not a de Polignac number, because 205104121 - 2³ = 205104113 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 205104095 and 205104104.

It is not an unprimeable number, because it can be changed into a prime (205104191) 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, 274566 + ... + 275311.

It is an arithmetic number, because the mean of its divisors is an integer number (51413593).

Almost surely, 2^205104121 is an apocalyptic number.

It is an amenable number.

205104121 is a deficient number, since it is larger than the sum of its proper divisors (550251).

205104121 is an equidigital number, since it uses as much as digits as its factorization.

205104121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550250.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 205104121 is about 14321.4566647391. The cubic root of 205104121 is about 589.7366640584.

Adding to 205104121 its reverse (121401502), we get a palindrome (326505623).

The spelling of 205104121 in words is "two hundred five million, one hundred four thousand, one hundred twenty-one".