21213543306133 has 4 divisors (see below), whose sum is σ = 21213552726828. Its totient is φ = 21213533885440.

The previous prime is 21213543306127. The next prime is 21213543306161. The reversal of 21213543306133 is 33160334531212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 7035554661444 + 14177988644689 = 2652462^2 + 3765367^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213543306133 - 2⁹ = 21213543305621 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21213543306092 and 21213543306101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213543307133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 874935 + ... + 6572107.

It is an arithmetic number, because the mean of its divisors is an integer number (5303388181707).

Almost surely, 2^{21213543306133} is an apocalyptic number.

It is an amenable number.

21213543306133 is a deficient number, since it is larger than the sum of its proper divisors (9420695).

21213543306133 is an equidigital number, since it uses as much as digits as its factorization.

21213543306133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9420694.

The product of its (nonzero) digits is 116640, while the sum is 37.

Adding to 21213543306133 its reverse (33160334531212), we get a palindrome (54373877837345).

The spelling of 21213543306133 in words is "twenty-one trillion, two hundred thirteen billion, five hundred forty-three million, three hundred six thousand, one hundred thirty-three".