21220243133 has 2 divisors, whose sum is σ = 21220243134. Its totient is φ = 21220243132.

The previous prime is 21220243129. The next prime is 21220243139. The reversal of 21220243133 is 33134202212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11500846564 + 9719396569 = 107242^2 + 98587^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220243133 - 2² = 21220243129 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220243099 and 21220243108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220243139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610121566 + 10610121567.

It is an arithmetic number, because the mean of its divisors is an integer number (10610121567).

Almost surely, 2^21220243133 is an apocalyptic number.

It is an amenable number.

21220243133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220243133 is an equidigital number, since it uses as much as digits as its factorization.

21220243133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21220243133 its reverse (33134202212), we get a palindrome (54354445345).

The spelling of 21220243133 in words is "twenty-one billion, two hundred twenty million, two hundred forty-three thousand, one hundred thirty-three".