21131222213113 has 4 divisors (see below), whose sum is σ = 21138608172708. Its totient is φ = 21123836253520.

The previous prime is 21131222213107. The next prime is 21131222213117. The reversal of 21131222213113 is 31131222213112.

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 11996580377664 + 9134641835449 = 3463608^2 + 3022357^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21131222213113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131222213117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3692975506 + ... + 3692981227.

It is an arithmetic number, because the mean of its divisors is an integer number (5284652043177).

Almost surely, 2^{21131222213113} is an apocalyptic number.

It is an amenable number.

21131222213113 is a deficient number, since it is larger than the sum of its proper divisors (7385959595).

21131222213113 is an equidigital number, since it uses as much as digits as its factorization.

21131222213113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7385959594.

The product of its digits is 864, while the sum is 25.

Adding to 21131222213113 its reverse (31131222213112), we get a palindrome (52262444426225).

Subtracting 21131222213113 from its reverse (31131222213112), we obtain a palindrome (9999999999999).

The spelling of 21131222213113 in words is "twenty-one trillion, one hundred thirty-one billion, two hundred twenty-two million, two hundred thirteen thousand, one hundred thirteen".