21112121113213 has 4 divisors (see below), whose sum is σ = 22736130429628. Its totient is φ = 19488111796800.

The previous prime is 21112121113183. The next prime is 21112121113217. The reversal of 21112121113213 is 31231112121112.

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 1832671552644 + 19279449560569 = 1353762^2 + 4390837^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112121113213 - 2⁹ = 21112121112701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112121113217) 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, 812004658188 + ... + 812004658213.

It is an arithmetic number, because the mean of its divisors is an integer number (5684032607407).

Almost surely, 2^{21112121113213} is an apocalyptic number.

It is an amenable number.

21112121113213 is a deficient number, since it is larger than the sum of its proper divisors (1624009316415).

21112121113213 is a wasteful number, since it uses less digits than its factorization.

21112121113213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1624009316414.

The product of its digits is 144, while the sum is 22.

Adding to 21112121113213 its reverse (31231112121112), we get a palindrome (52343233234325).

The spelling of 21112121113213 in words is "twenty-one trillion, one hundred twelve billion, one hundred twenty-one million, one hundred thirteen thousand, two hundred thirteen".