21203230211 has 4 divisors (see below), whose sum is σ = 21696328632. Its totient is φ = 20710131792.

The previous prime is 21203230187. The next prime is 21203230219. The reversal of 21203230211 is 11203230212.

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

It is a cyclic number.

It is not a de Polignac number, because 21203230211 - 2³⁰ = 20129488387 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21203230211.

It is not an unprimeable number, because it can be changed into a prime (21203230219) 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, 246549146 + ... + 246549231.

It is an arithmetic number, because the mean of its divisors is an integer number (5424082158).

Almost surely, 2^21203230211 is an apocalyptic number.

21203230211 is a deficient number, since it is larger than the sum of its proper divisors (493098421).

21203230211 is an equidigital number, since it uses as much as digits as its factorization.

21203230211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 493098420.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21203230211 its reverse (11203230212), we get a palindrome (32406460423).

Subtracting from 21203230211 its reverse (11203230212), we obtain a palindrome (9999999999).

The spelling of 21203230211 in words is "twenty-one billion, two hundred three million, two hundred thirty thousand, two hundred eleven".