21213543313253 has 2 divisors, whose sum is σ = 21213543313254. Its totient is φ = 21213543313252.

The previous prime is 21213543313213. The next prime is 21213543313271. The reversal of 21213543313253 is 35231334531212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12125591481124 + 9087951832129 = 3482182^2 + 3014623^2 .

It is a cyclic number.

It is not a de Polignac number, because 21213543313253 - 2¹⁶ = 21213543247717 is a prime.

It is a super-2 number, since 2×21213543313253² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21213543313213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606771656626 + 10606771656627.

It is an arithmetic number, because the mean of its divisors is an integer number (10606771656627).

Almost surely, 2^{21213543313253} is an apocalyptic number.

It is an amenable number.

21213543313253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213543313253 is an equidigital number, since it uses as much as digits as its factorization.

21213543313253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 194400, while the sum is 38.

Adding to 21213543313253 its reverse (35231334531212), we get a palindrome (56444877844465).

The spelling of 21213543313253 in words is "twenty-one trillion, two hundred thirteen billion, five hundred forty-three million, three hundred thirteen thousand, two hundred fifty-three".