21022133221 has 4 divisors (see below), whose sum is σ = 21022729132. Its totient is φ = 21021537312.

The previous prime is 21022133213. The next prime is 21022133299. The reversal of 21022133221 is 12233122012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6949056321 + 14073076900 = 83361^2 + 118630^2 .

It is a cyclic number.

It is not a de Polignac number, because 21022133221 - 2³ = 21022133213 is a prime.

It is a super-2 number, since 2×21022133221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022133021) 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, 241470 + ... + 316783.

It is an arithmetic number, because the mean of its divisors is an integer number (5255682283).

Almost surely, 2^21022133221 is an apocalyptic number.

It is an amenable number.

21022133221 is a deficient number, since it is larger than the sum of its proper divisors (595911).

21022133221 is an equidigital number, since it uses as much as digits as its factorization.

21022133221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 595910.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21022133221 its reverse (12233122012), we get a palindrome (33255255233).

The spelling of 21022133221 in words is "twenty-one billion, twenty-two million, one hundred thirty-three thousand, two hundred twenty-one".