21203430011 has 4 divisors (see below), whose sum is σ = 21934582800. Its totient is φ = 20472277224.

The previous prime is 21203430007. The next prime is 21203430091. The reversal of 21203430011 is 11003430212.

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 21203430011 - 2² = 21203430007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21203430091) 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, 365576351 + ... + 365576408.

It is an arithmetic number, because the mean of its divisors is an integer number (5483645700).

Almost surely, 2^21203430011 is an apocalyptic number.

21203430011 is a deficient number, since it is larger than the sum of its proper divisors (731152789).

21203430011 is an equidigital number, since it uses as much as digits as its factorization.

21203430011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 731152788.

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

Adding to 21203430011 its reverse (11003430212), we get a palindrome (32206860223).

The spelling of 21203430011 in words is "twenty-one billion, two hundred three million, four hundred thirty thousand, eleven".