21213223321 has 4 divisors (see below), whose sum is σ = 21306673872. Its totient is φ = 21119772772.

The previous prime is 21213223307. The next prime is 21213223391. The reversal of 21213223321 is 12332231212.

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 21213223321 - 2¹¹ = 21213221273 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21213223292 and 21213223301.

It is not an unprimeable number, because it can be changed into a prime (21213223391) 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, 46724935 + ... + 46725388.

It is an arithmetic number, because the mean of its divisors is an integer number (5326668468).

Almost surely, 2^21213223321 is an apocalyptic number.

It is an amenable number.

21213223321 is a deficient number, since it is larger than the sum of its proper divisors (93450551).

21213223321 is an equidigital number, since it uses as much as digits as its factorization.

21213223321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93450550.

The product of its digits is 864, while the sum is 22.

Adding to 21213223321 its reverse (12332231212), we get a palindrome (33545454533).

The spelling of 21213223321 in words is "twenty-one billion, two hundred thirteen million, two hundred twenty-three thousand, three hundred twenty-one".