13211210421221 has 4 divisors (see below), whose sum is σ = 13211249801100. Its totient is φ = 13211171041344.

The previous prime is 13211210421173. The next prime is 13211210421239. The reversal of 13211210421221 is 12212401211231.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9096925564321 + 4114284856900 = 3016111^2 + 2028370^2 .

It is a cyclic number.

It is not a de Polignac number, because 13211210421221 - 2¹⁴ = 13211210404837 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13211210451221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19182356 + ... + 19859133.

It is an arithmetic number, because the mean of its divisors is an integer number (3302812450275).

Almost surely, 2^{13211210421221} is an apocalyptic number.

It is an amenable number.

13211210421221 is a deficient number, since it is larger than the sum of its proper divisors (39379879).

13211210421221 is an equidigital number, since it uses as much as digits as its factorization.

13211210421221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39379878.

The product of its (nonzero) digits is 384, while the sum is 23.

Adding to 13211210421221 its reverse (12212401211231), we get a palindrome (25423611632452).

The spelling of 13211210421221 in words is "thirteen trillion, two hundred eleven billion, two hundred ten million, four hundred twenty-one thousand, two hundred twenty-one".