21021231331213 has 4 divisors (see below), whose sum is σ = 21050146368160. Its totient is φ = 20992316294268.

The previous prime is 21021231331189. The next prime is 21021231331231. The reversal of 21021231331213 is 31213313212012.

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 a de Polignac number, because none of the positive numbers 2^k-21021231331213 is a prime.

It is a super-2 number, since 2×21021231331213² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021231331613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14457517383 + ... + 14457518836.

It is an arithmetic number, because the mean of its divisors is an integer number (5262536592040).

Almost surely, 2^{21021231331213} is an apocalyptic number.

It is an amenable number.

21021231331213 is a deficient number, since it is larger than the sum of its proper divisors (28915036947).

21021231331213 is an equidigital number, since it uses as much as digits as its factorization.

21021231331213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28915036946.

The product of its (nonzero) digits is 1296, while the sum is 25.

Adding to 21021231331213 its reverse (31213313212012), we get a palindrome (52234544543225).

The spelling of 21021231331213 in words is "twenty-one trillion, twenty-one billion, two hundred thirty-one million, three hundred thirty-one thousand, two hundred thirteen".