21304050205 has 4 divisors (see below), whose sum is σ = 25564860252. Its totient is φ = 17043240160.

The previous prime is 21304050203. The next prime is 21304050331. The reversal of 21304050205 is 50205040312.

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 12982779364 + 8321270841 = 113942^2 + 91221^2 .

It is not a de Polignac number, because 21304050205 - 2¹ = 21304050203 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 (21304050203) 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, 2130405016 + ... + 2130405025.

It is an arithmetic number, because the mean of its divisors is an integer number (6391215063).

Almost surely, 2^21304050205 is an apocalyptic number.

It is an amenable number.

21304050205 is a deficient number, since it is larger than the sum of its proper divisors (4260810047).

21304050205 is an equidigital number, since it uses as much as digits as its factorization.

21304050205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4260810046.

The product of its (nonzero) digits is 1200, while the sum is 22.

Adding to 21304050205 its reverse (50205040312), we get a palindrome (71509090517).

The spelling of 21304050205 in words is "twenty-one billion, three hundred four million, fifty thousand, two hundred five".