21434241343421 has 4 divisors (see below), whose sum is σ = 21646461554844. Its totient is φ = 21222021132000.

The previous prime is 21434241343409. The next prime is 21434241343561. The reversal of 21434241343421 is 12434314243412.

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

It can be written as a sum of positive squares in 2 ways, for example, as 14474326776196 + 6959914567225 = 3804514^2 + 2638165^2 .

It is a cyclic number.

It is not a de Polignac number, because 21434241343421 - 2¹⁸ = 21434241081277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21434241346421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106110105560 + ... + 106110105761.

It is an arithmetic number, because the mean of its divisors is an integer number (5411615388711).

Almost surely, 2^{21434241343421} is an apocalyptic number.

It is an amenable number.

21434241343421 is a deficient number, since it is larger than the sum of its proper divisors (212220211423).

21434241343421 is a wasteful number, since it uses less digits than its factorization.

21434241343421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212220211422.

The product of its digits is 221184, while the sum is 38.

Adding to 21434241343421 its reverse (12434314243412), we get a palindrome (33868555586833).

The spelling of 21434241343421 in words is "twenty-one trillion, four hundred thirty-four billion, two hundred forty-one million, three hundred forty-three thousand, four hundred twenty-one".