21011221203 has 16 divisors (see below), whose sum is σ = 32468046336. Its totient is φ = 11837306880.

The previous prime is 21011221181. The next prime is 21011221223. The reversal of 21011221203 is 30212211012.

It is not a de Polignac number, because 21011221203 - 2⁸ = 21011220947 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21011221223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7044526 + ... + 7047507.

It is an arithmetic number, because the mean of its divisors is an integer number (2029252896).

Almost surely, 2^21011221203 is an apocalyptic number.

21011221203 is a deficient number, since it is larger than the sum of its proper divisors (11456825133).

21011221203 is a wasteful number, since it uses less digits than its factorization.

21011221203 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14092114.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21011221203 its reverse (30212211012), we get a palindrome (51223432215).

The spelling of 21011221203 in words is "twenty-one billion, eleven million, two hundred twenty-one thousand, two hundred three".