13126211516221 has 4 divisors (see below), whose sum is σ = 13126760501344. Its totient is φ = 13125662531100.

The previous prime is 13126211516149. The next prime is 13126211516329. The reversal of 13126211516221 is 12261511262131.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 13126211516221 - 2²¹ = 13126209419069 is a prime.

It is a super-2 number, since 2×13126211516221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13126211516521) 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, 274456695 + ... + 274504516.

It is an arithmetic number, because the mean of its divisors is an integer number (3281690125336).

Almost surely, 2^{13126211516221} is an apocalyptic number.

It is an amenable number.

13126211516221 is a deficient number, since it is larger than the sum of its proper divisors (548985123).

13126211516221 is an equidigital number, since it uses as much as digits as its factorization.

13126211516221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548985122.

The product of its digits is 8640, while the sum is 34.

Adding to 13126211516221 its reverse (12261511262131), we get a palindrome (25387722778352).

The spelling of 13126211516221 in words is "thirteen trillion, one hundred twenty-six billion, two hundred eleven million, five hundred sixteen thousand, two hundred twenty-one".