21332111221 has 2 divisors, whose sum is σ = 21332111222. Its totient is φ = 21332111220.

The previous prime is 21332111209. The next prime is 21332111237. The reversal of 21332111221 is 12211123312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16095996900 + 5236114321 = 126870^2 + 72361^2 .

It is a cyclic number.

It is not a de Polignac number, because 21332111221 - 2²³ = 21323722613 is a prime.

It is a super-2 number, since 2×21332111221² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21332111291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666055610 + 10666055611.

It is an arithmetic number, because the mean of its divisors is an integer number (10666055611).

Almost surely, 2^21332111221 is an apocalyptic number.

It is an amenable number.

21332111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21332111221 is an equidigital number, since it uses as much as digits as its factorization.

21332111221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 144, while the sum is 19.

Adding to 21332111221 its reverse (12211123312), we get a palindrome (33543234533).

The spelling of 21332111221 in words is "twenty-one billion, three hundred thirty-two million, one hundred eleven thousand, two hundred twenty-one".