204207021 has 16 divisors (see below), whose sum is σ = 306361600. Its totient is φ = 134413344.

The previous prime is 204206999. The next prime is 204207037. The reversal of 204207021 is 120702402.

It is not a de Polignac number, because 204207021 - 2²⁵ = 170652589 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 204206985 and 204207003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204207221) 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 15 ways as a sum of consecutive naturals, for example, 45736 + ... + 50001.

It is an arithmetic number, because the mean of its divisors is an integer number (19147600).

Almost surely, 2^204207021 is an apocalyptic number.

It is an amenable number.

204207021 is a deficient number, since it is larger than the sum of its proper divisors (102154579).

204207021 is an equidigital number, since it uses as much as digits as its factorization.

204207021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95825 (or 95819 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 18.

The square root of 204207021 is about 14290.1022039732. The cubic root of 204207021 is about 588.8755957457.

Adding to 204207021 its reverse (120702402), we get a palindrome (324909423).

The spelling of 204207021 in words is "two hundred four million, two hundred seven thousand, twenty-one".