21213321213 has 8 divisors (see below), whose sum is σ = 32325060928. Its totient is φ = 12121897824.

The previous prime is 21213321211. The next prime is 21213321247. The reversal of 21213321213 is 31212331212.

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

It is not a de Polignac number, because 21213321213 - 2¹ = 21213321211 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 1010158153 = 21213321213 / (2 + 1 + 2 + 1 + 3 + 3 + 2 + 1 + 2 + 1 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21213321213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213321211) 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, 505079056 + ... + 505079097.

It is an arithmetic number, because the mean of its divisors is an integer number (4040632616).

Almost surely, 2^21213321213 is an apocalyptic number.

It is an amenable number.

21213321213 is a deficient number, since it is larger than the sum of its proper divisors (11111739715).

21213321213 is a wasteful number, since it uses less digits than its factorization.

21213321213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010158163.

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

Adding to 21213321213 its reverse (31212331212), we get a palindrome (52425652425).

Subtracting 21213321213 from its reverse (31212331212), we obtain a palindrome (9999009999).

The spelling of 21213321213 in words is "twenty-one billion, two hundred thirteen million, three hundred twenty-one thousand, two hundred thirteen".