21212033021213 has 4 divisors (see below), whose sum is σ = 21219206521980. Its totient is φ = 21204859520448.

The previous prime is 21212033021183. The next prime is 21212033021251. The reversal of 21212033021213 is 31212033021212.

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 4491801255769 + 16720231765444 = 2119387^2 + 4089038^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212033021213 - 2¹² = 21212033017117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212033021273) 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, 3586745948 + ... + 3586751861.

It is an arithmetic number, because the mean of its divisors is an integer number (5304801630495).

Almost surely, 2^{21212033021213} is an apocalyptic number.

It is an amenable number.

21212033021213 is a deficient number, since it is larger than the sum of its proper divisors (7173500767).

21212033021213 is an equidigital number, since it uses as much as digits as its factorization.

21212033021213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7173500766.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21212033021213 its reverse (31212033021212), we get a palindrome (52424066042425).

Subtracting 21212033021213 from its reverse (31212033021212), we obtain a palindrome (9999999999999).

The spelling of 21212033021213 in words is "twenty-one trillion, two hundred twelve billion, thirty-three million, twenty-one thousand, two hundred thirteen".