205225021 has 12 divisors (see below), whose sum is σ = 216156640. Its totient is φ = 194820120.

The previous prime is 205224989. The next prime is 205225039. The reversal of 205225021 is 120522502.

It is not a de Polignac number, because 205225021 - 2⁵ = 205224989 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 205225021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205225081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72136 + ... + 74926.

Almost surely, 2^205225021 is an apocalyptic number.

It is an amenable number.

205225021 is a deficient number, since it is larger than the sum of its proper divisors (10931619).

205225021 is a wasteful number, since it uses less digits than its factorization.

205225021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2976 (or 2953 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 19.

The square root of 205225021 is about 14325.6769822581. The cubic root of 205225021 is about 589.8525160423.

Adding to 205225021 its reverse (120522502), we get a palindrome (325747523).

The spelling of 205225021 in words is "two hundred five million, two hundred twenty-five thousand, twenty-one".