21343121409 has 4 divisors (see below), whose sum is σ = 28457495216. Its totient is φ = 14228747604.

The previous prime is 21343121407. The next prime is 21343121431. The reversal of 21343121409 is 90412134312.

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 not a de Polignac number, because 21343121409 - 2¹ = 21343121407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21343121407) 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, 3557186899 + ... + 3557186904.

It is an arithmetic number, because the mean of its divisors is an integer number (7114373804).

Almost surely, 2^21343121409 is an apocalyptic number.

It is an amenable number.

21343121409 is a deficient number, since it is larger than the sum of its proper divisors (7114373807).

21343121409 is an equidigital number, since it uses as much as digits as its factorization.

21343121409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7114373806.

The product of its (nonzero) digits is 5184, while the sum is 30.

The spelling of 21343121409 in words is "twenty-one billion, three hundred forty-three million, one hundred twenty-one thousand, four hundred nine".