21121222212113 has 4 divisors (see below), whose sum is σ = 21126089979120. Its totient is φ = 21116354445108.

The previous prime is 21121222212067. The next prime is 21121222212143. The reversal of 21121222212113 is 31121222212112.

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 21121222212113 - 2¹⁴ = 21121222195729 is a prime.

It is a super-2 number, since 2×21121222212113² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21121222212143) 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, 2433876995 + ... + 2433885672.

It is an arithmetic number, because the mean of its divisors is an integer number (5281522494780).

Almost surely, 2^{21121222212113} is an apocalyptic number.

It is an amenable number.

21121222212113 is a deficient number, since it is larger than the sum of its proper divisors (4867767007).

21121222212113 is an equidigital number, since it uses as much as digits as its factorization.

21121222212113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4867767006.

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

Adding to 21121222212113 its reverse (31121222212112), we get a palindrome (52242444424225).

Subtracting 21121222212113 from its reverse (31121222212112), we obtain a palindrome (9999999999999).

The spelling of 21121222212113 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, one hundred thirteen".