21040203211 has 4 divisors (see below), whose sum is σ = 21042261592. Its totient is φ = 21038144832.

The previous prime is 21040203203. The next prime is 21040203229. The reversal of 21040203211 is 11230204012.

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 21040203211 - 2³ = 21040203203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21040203011) 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, 1013781 + ... + 1034326.

It is an arithmetic number, because the mean of its divisors is an integer number (5260565398).

Almost surely, 2^21040203211 is an apocalyptic number.

21040203211 is a deficient number, since it is larger than the sum of its proper divisors (2058381).

21040203211 is a wasteful number, since it uses less digits than its factorization.

21040203211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2058380.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21040203211 its reverse (11230204012), we get a palindrome (32270407223).

The spelling of 21040203211 in words is "twenty-one billion, forty million, two hundred three thousand, two hundred eleven".