204501610421 has 4 divisors (see below), whose sum is σ = 204945215244. Its totient is φ = 204058005600.

The previous prime is 204501610361. The next prime is 204501610429. The reversal of 204501610421 is 124016105402.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 153205702225 + 51295908196 = 391415^2 + 226486^2 .

It is a cyclic number.

It is not a de Polignac number, because 204501610421 - 2¹⁰ = 204501609397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (204501610429) 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, 221801720 + ... + 221802641.

It is an arithmetic number, because the mean of its divisors is an integer number (51236303811).

Almost surely, 2^204501610421 is an apocalyptic number.

It is an amenable number.

204501610421 is a deficient number, since it is larger than the sum of its proper divisors (443604823).

204501610421 is an equidigital number, since it uses as much as digits as its factorization.

204501610421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 443604822.

The product of its (nonzero) digits is 1920, while the sum is 26.

Adding to 204501610421 its reverse (124016105402), we get a palindrome (328517715823).

The spelling of 204501610421 in words is "two hundred four billion, five hundred one million, six hundred ten thousand, four hundred twenty-one".