21311013133 has 2 divisors, whose sum is σ = 21311013134. Its totient is φ = 21311013132.

The previous prime is 21311013083. The next prime is 21311013137. The reversal of 21311013133 is 33131011312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15076647369 + 6234365764 = 122787^2 + 78958^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311013133 - 2⁹ = 21311012621 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21311013133.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21311013137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10655506566 + 10655506567.

It is an arithmetic number, because the mean of its divisors is an integer number (10655506567).

Almost surely, 2^21311013133 is an apocalyptic number.

It is an amenable number.

21311013133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21311013133 is an equidigital number, since it uses as much as digits as its factorization.

21311013133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162, while the sum is 19.

Adding to 21311013133 its reverse (33131011312), we get a palindrome (54442024445).

The spelling of 21311013133 in words is "twenty-one billion, three hundred eleven million, thirteen thousand, one hundred thirty-three".