21212113113113 has 4 divisors (see below), whose sum is σ = 22843814121828. Its totient is φ = 19580412104400.

The previous prime is 21212113113067. The next prime is 21212113113143. The reversal of 21212113113113 is 31131131121212.

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 2355571135369 + 18856541977744 = 1534787^2 + 4342412^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212113113113 - 2¹⁰ = 21212113112089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212113113143) 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, 815850504338 + ... + 815850504363.

It is an arithmetic number, because the mean of its divisors is an integer number (5710953530457).

Almost surely, 2^{21212113113113} is an apocalyptic number.

It is an amenable number.

21212113113113 is a deficient number, since it is larger than the sum of its proper divisors (1631701008715).

21212113113113 is a wasteful number, since it uses less digits than its factorization.

21212113113113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631701008714.

The product of its digits is 216, while the sum is 23.

Adding to 21212113113113 its reverse (31131131121212), we get a palindrome (52343244234325).

The spelling of 21212113113113 in words is "twenty-one trillion, two hundred twelve billion, one hundred thirteen million, one hundred thirteen thousand, one hundred thirteen".