205121027 has 4 divisors (see below), whose sum is σ = 205149840. Its totient is φ = 205092216.

The previous prime is 205121023. The next prime is 205121039. The reversal of 205121027 is 720121502.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 720121502 = 2 ⋅360060751.

It is a cyclic number.

It is not a de Polignac number, because 205121027 - 2² = 205121023 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is not an unprimeable number, because it can be changed into a prime (205121023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4874 + ... + 20832.

It is an arithmetic number, because the mean of its divisors is an integer number (51287460).

Almost surely, 2^205121027 is an apocalyptic number.

205121027 is a deficient number, since it is larger than the sum of its proper divisors (28813).

205121027 is a wasteful number, since it uses less digits than its factorization.

205121027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28812.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 205121027 is about 14322.0468858330. The cubic root of 205121027 is about 589.7528669087.

Adding to 205121027 its reverse (720121502), we get a palindrome (925242529).

The spelling of 205121027 in words is "two hundred five million, one hundred twenty-one thousand, twenty-seven".