21300205 has 4 divisors (see below), whose sum is σ = 25560252. Its totient is φ = 17040160.

The previous prime is 21300203. The next prime is 21300233. The reversal of 21300205 is 50200312.

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 6160324 + 15139881 = 2482^2 + 3891^2 .

It is not a de Polignac number, because 21300205 - 2¹ = 21300203 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 (21300203) 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, 2130016 + ... + 2130025.

It is an arithmetic number, because the mean of its divisors is an integer number (6390063).

Almost surely, 2^21300205 is an apocalyptic number.

It is an amenable number.

21300205 is a deficient number, since it is larger than the sum of its proper divisors (4260047).

21300205 is an equidigital number, since it uses as much as digits as its factorization.

21300205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4260046.

The product of its (nonzero) digits is 60, while the sum is 13.

The square root of 21300205 is about 4615.2145128910. The cubic root of 21300205 is about 277.2008734677.

Adding to 21300205 its reverse (50200312), we get a palindrome (71500517).

The spelling of 21300205 in words is "twenty-one million, three hundred thousand, two hundred five".