21404241321 has 4 divisors (see below), whose sum is σ = 28538988432. Its totient is φ = 14269494212.

The previous prime is 21404241319. The next prime is 21404241329. The reversal of 21404241321 is 12314240412.

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 21404241321 - 2¹ = 21404241319 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21404241291 and 21404241300.

It is not an unprimeable number, because it can be changed into a prime (21404241329) 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, 3567373551 + ... + 3567373556.

It is an arithmetic number, because the mean of its divisors is an integer number (7134747108).

Almost surely, 2^21404241321 is an apocalyptic number.

It is an amenable number.

21404241321 is a deficient number, since it is larger than the sum of its proper divisors (7134747111).

21404241321 is an equidigital number, since it uses as much as digits as its factorization.

21404241321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7134747110.

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21404241321 its reverse (12314240412), we get a palindrome (33718481733).

Subtracting from 21404241321 its reverse (12314240412), we obtain a palindrome (9090000909).

The spelling of 21404241321 in words is "twenty-one billion, four hundred four million, two hundred forty-one thousand, three hundred twenty-one".