21133011221 has 8 divisors (see below), whose sum is σ = 24165757440. Its totient is φ = 18103701168.

The previous prime is 21133011217. The next prime is 21133011247. The reversal of 21133011221 is 12211033112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21133011221 - 2² = 21133011217 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 21133011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133011121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 845846 + ... + 870471.

It is an arithmetic number, because the mean of its divisors is an integer number (3020719680).

Almost surely, 2^21133011221 is an apocalyptic number.

It is an amenable number.

21133011221 is a deficient number, since it is larger than the sum of its proper divisors (3032746219).

21133011221 is a wasteful number, since it uses less digits than its factorization.

21133011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718083.

The product of its (nonzero) digits is 72, while the sum is 17.

Adding to 21133011221 its reverse (12211033112), we get a palindrome (33344044333).

The spelling of 21133011221 in words is "twenty-one billion, one hundred thirty-three million, eleven thousand, two hundred twenty-one".