21133132221 has 4 divisors (see below), whose sum is σ = 28177509632. Its totient is φ = 14088754812.

The previous prime is 21133132219. The next prime is 21133132249. The reversal of 21133132221 is 12223133112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21133132221 - 2¹ = 21133132219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21133132421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3522188701 + ... + 3522188706.

It is an arithmetic number, because the mean of its divisors is an integer number (7044377408).

Almost surely, 2^21133132221 is an apocalyptic number.

It is an amenable number.

21133132221 is a deficient number, since it is larger than the sum of its proper divisors (7044377411).

21133132221 is an equidigital number, since it uses as much as digits as its factorization.

21133132221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7044377410.

The product of its digits is 432, while the sum is 21.

Adding to 21133132221 its reverse (12223133112), we get a palindrome (33356265333).

The spelling of 21133132221 in words is "twenty-one billion, one hundred thirty-three million, one hundred thirty-two thousand, two hundred twenty-one".