21144313221 has 8 divisors (see below), whose sum is σ = 29164570080. Its totient is φ = 13610132592.

The previous prime is 21144313213. The next prime is 21144313243. The reversal of 21144313221 is 12231344112.

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

It is not a de Polignac number, because 21144313221 - 2³ = 21144313213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21144313191 and 21144313200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144313721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 121518955 + ... + 121519128.

It is an arithmetic number, because the mean of its divisors is an integer number (3645571260).

Almost surely, 2^21144313221 is an apocalyptic number.

It is an amenable number.

21144313221 is a deficient number, since it is larger than the sum of its proper divisors (8020256859).

21144313221 is a wasteful number, since it uses less digits than its factorization.

21144313221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243038115.

The product of its digits is 1152, while the sum is 24.

Adding to 21144313221 its reverse (12231344112), we get a palindrome (33375657333).

The spelling of 21144313221 in words is "twenty-one billion, one hundred forty-four million, three hundred thirteen thousand, two hundred twenty-one".