21331302121 has 4 divisors (see below), whose sum is σ = 21346045312. Its totient is φ = 21316558932.

The previous prime is 21331302119. The next prime is 21331302169. The reversal of 21331302121 is 12120313312.

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 21331302121 - 2¹ = 21331302119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21331302191) 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, 7369425 + ... + 7372318.

It is an arithmetic number, because the mean of its divisors is an integer number (5336511328).

Almost surely, 2^21331302121 is an apocalyptic number.

It is an amenable number.

21331302121 is a deficient number, since it is larger than the sum of its proper divisors (14743191).

21331302121 is a wasteful number, since it uses less digits than its factorization.

21331302121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14743190.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21331302121 its reverse (12120313312), we get a palindrome (33451615433).

The spelling of 21331302121 in words is "twenty-one billion, three hundred thirty-one million, three hundred two thousand, one hundred twenty-one".