21040204411221 has 32 divisors (see below), whose sum is σ = 30471849934848. Its totient is φ = 12862868540160.

The previous prime is 21040204411181. The next prime is 21040204411253. The reversal of 21040204411221 is 12211440204012.

It is a happy number.

It is not a de Polignac number, because 21040204411221 - 2¹⁸ = 21040204149077 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21040204411191 and 21040204411200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21040204418221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19146465 + ... + 20215526.

It is an arithmetic number, because the mean of its divisors is an integer number (952245310464).

Almost surely, 2^{21040204411221} is an apocalyptic number.

It is an amenable number.

21040204411221 is a deficient number, since it is larger than the sum of its proper divisors (9431645523627).

21040204411221 is a wasteful number, since it uses less digits than its factorization.

21040204411221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39362281.

The product of its (nonzero) digits is 1024, while the sum is 24.

Adding to 21040204411221 its reverse (12211440204012), we get a palindrome (33251644615233).

The spelling of 21040204411221 in words is "twenty-one trillion, forty billion, two hundred four million, four hundred eleven thousand, two hundred twenty-one".