21221203323 has 4 divisors (see below), whose sum is σ = 28294937768. Its totient is φ = 14147468880.

The previous prime is 21221203307. The next prime is 21221203327. The reversal of 21221203323 is 32330212212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21221203323 - 2⁴ = 21221203307 is a prime.

It is a super-2 number, since 2×21221203323² (a number of 21 digits) contains 22 as substring.

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 21221203323.

It is not an unprimeable number, because it can be changed into a prime (21221203327) 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, 3536867218 + ... + 3536867223.

It is an arithmetic number, because the mean of its divisors is an integer number (7073734442).

Almost surely, 2^21221203323 is an apocalyptic number.

21221203323 is a deficient number, since it is larger than the sum of its proper divisors (7073734445).

21221203323 is an equidigital number, since it uses as much as digits as its factorization.

21221203323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7073734444.

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21221203323 its reverse (32330212212), we get a palindrome (53551415535).

The spelling of 21221203323 in words is "twenty-one billion, two hundred twenty-one million, two hundred three thousand, three hundred twenty-three".