21212013331021 has 4 divisors (see below), whose sum is σ = 21296523344544. Its totient is φ = 21127503317500.

The previous prime is 21212013330953. The next prime is 21212013331031. The reversal of 21212013331021 is 12013331021212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21212013331021 - 2⁹ = 21212013330509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21212013330983 and 21212013331001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212013331031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42255006385 + ... + 42255006886.

It is an arithmetic number, because the mean of its divisors is an integer number (5324130836136).

Almost surely, 2^{21212013331021} is an apocalyptic number.

It is an amenable number.

21212013331021 is a deficient number, since it is larger than the sum of its proper divisors (84510013523).

21212013331021 is an equidigital number, since it uses as much as digits as its factorization.

21212013331021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84510013522.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21212013331021 its reverse (12013331021212), we get a palindrome (33225344352233).

The spelling of 21212013331021 in words is "twenty-one trillion, two hundred twelve billion, thirteen million, three hundred thirty-one thousand, twenty-one".