21205323630203 has 2 divisors, whose sum is σ = 21205323630204. Its totient is φ = 21205323630202.

The previous prime is 21205323630187. The next prime is 21205323630259. The reversal of 21205323630203 is 30203632350212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21205323630203 - 2⁴ = 21205323630187 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21205323630203.

It is not a weakly prime, because it can be changed into another prime (21205323630503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602661815101 + 10602661815102.

It is an arithmetic number, because the mean of its divisors is an integer number (10602661815102).

Almost surely, 2^{21205323630203} is an apocalyptic number.

21205323630203 is a deficient number, since it is larger than the sum of its proper divisors (1).

21205323630203 is an equidigital number, since it uses as much as digits as its factorization.

21205323630203 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38880, while the sum is 32.

Adding to 21205323630203 its reverse (30203632350212), we get a palindrome (51408955980415).

The spelling of 21205323630203 in words is "twenty-one trillion, two hundred five billion, three hundred twenty-three million, six hundred thirty thousand, two hundred three".