21211212133 has 2 divisors, whose sum is σ = 21211212134. Its totient is φ = 21211212132.

The previous prime is 21211212109. The next prime is 21211212173. The reversal of 21211212133 is 33121211212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11053999044 + 10157213089 = 105138^2 + 100783^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211212133 - 2³³ = 12621277541 is a prime.

It is a super-2 number, since 2×21211212133² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21211212133.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211212173) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605606066 + 10605606067.

It is an arithmetic number, because the mean of its divisors is an integer number (10605606067).

Almost surely, 2^21211212133 is an apocalyptic number.

It is an amenable number.

21211212133 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211212133 is an equidigital number, since it uses as much as digits as its factorization.

21211212133 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 21211212133 its reverse (33121211212), we get a palindrome (54332423345).

The spelling of 21211212133 in words is "twenty-one billion, two hundred eleven million, two hundred twelve thousand, one hundred thirty-three".