21311223120113 has 4 divisors (see below), whose sum is σ = 21387063772068. Its totient is φ = 21235382468160.

The previous prime is 21311223120091. The next prime is 21311223120169. The reversal of 21311223120113 is 31102132211312.

It is a happy number.

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 18420379858609 + 2890843261504 = 4291897^2 + 1700248^2 .

It is a cyclic number.

It is not a de Polignac number, because 21311223120113 - 2¹⁰ = 21311223119089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21311223122113) 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, 37920325556 + ... + 37920326117.

It is an arithmetic number, because the mean of its divisors is an integer number (5346765943017).

Almost surely, 2^{21311223120113} is an apocalyptic number.

It is an amenable number.

21311223120113 is a deficient number, since it is larger than the sum of its proper divisors (75840651955).

21311223120113 is an equidigital number, since it uses as much as digits as its factorization.

21311223120113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75840651954.

The product of its (nonzero) digits is 432, while the sum is 23.

Adding to 21311223120113 its reverse (31102132211312), we get a palindrome (52413355331425).

The spelling of 21311223120113 in words is "twenty-one trillion, three hundred eleven billion, two hundred twenty-three million, one hundred twenty thousand, one hundred thirteen".