21331221213 has 8 divisors (see below), whose sum is σ = 28445198400. Its totient is φ = 14219029088.

The previous prime is 21331221161. The next prime is 21331221217. The reversal of 21331221213 is 31212213312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21331221213 - 2¹³ = 21331213021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21331221213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331221217) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 418128 + ... + 466361.

It is an arithmetic number, because the mean of its divisors is an integer number (3555649800).

Almost surely, 2^21331221213 is an apocalyptic number.

It is an amenable number.

21331221213 is a deficient number, since it is larger than the sum of its proper divisors (7113977187).

21331221213 is an equidigital number, since it uses as much as digits as its factorization.

21331221213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 892531.

The product of its digits is 432, while the sum is 21.

Adding to 21331221213 its reverse (31212213312), we get a palindrome (52543434525).

The spelling of 21331221213 in words is "twenty-one billion, three hundred thirty-one million, two hundred twenty-one thousand, two hundred thirteen".