205121025 has 48 divisors (see below), whose sum is σ = 378745600. Its totient is φ = 108838080.

The previous prime is 205121023. The next prime is 205121039. The reversal of 205121025 is 520121502.

It is not a de Polignac number, because 205121025 - 2¹ = 205121023 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205120989 and 205121007.

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

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 153912 + ... + 155238.

Almost surely, 2^205121025 is an apocalyptic number.

205121025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

205121025 is a deficient number, since it is larger than the sum of its proper divisors (173624575).

205121025 is a wasteful number, since it uses less digits than its factorization.

205121025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1575 (or 1564 counting only the distinct ones).

The product of its (nonzero) digits is 200, while the sum is 18.

The square root of 205121025 is about 14322.0468160106. The cubic root of 205121025 is about 589.7528649919.

Adding to 205121025 its reverse (520121502), we get a palindrome (725242527).

The spelling of 205121025 in words is "two hundred five million, one hundred twenty-one thousand, twenty-five".