21013411421 has 4 divisors (see below), whose sum is σ = 21051827712. Its totient is φ = 20974995132.

The previous prime is 21013411417. The next prime is 21013411427. The reversal of 21013411421 is 12411431012.

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 21013411421 - 2² = 21013411417 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21013411393 and 21013411402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21013411427) 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, 19207325 + ... + 19208418.

It is an arithmetic number, because the mean of its divisors is an integer number (5262956928).

Almost surely, 2^21013411421 is an apocalyptic number.

It is an amenable number.

21013411421 is a deficient number, since it is larger than the sum of its proper divisors (38416291).

21013411421 is an equidigital number, since it uses as much as digits as its factorization.

21013411421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38416290.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21013411421 its reverse (12411431012), we get a palindrome (33424842433).

The spelling of 21013411421 in words is "twenty-one billion, thirteen million, four hundred eleven thousand, four hundred twenty-one".