21304234331 has 4 divisors (see below), whose sum is σ = 21304536000. Its totient is φ = 21303932664.

The previous prime is 21304234283. The next prime is 21304234363. The reversal of 21304234331 is 13343240312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21304234331 is a prime.

It is a super-2 number, since 2×21304234331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21304234331.

It is not an unprimeable number, because it can be changed into a prime (21304234531) 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, 18365 + ... + 207233.

It is an arithmetic number, because the mean of its divisors is an integer number (5326134000).

Almost surely, 2^21304234331 is an apocalyptic number.

21304234331 is a deficient number, since it is larger than the sum of its proper divisors (301669).

21304234331 is a wasteful number, since it uses less digits than its factorization.

21304234331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301668.

The product of its (nonzero) digits is 5184, while the sum is 26.

Adding to 21304234331 its reverse (13343240312), we get a palindrome (34647474643).

The spelling of 21304234331 in words is "twenty-one billion, three hundred four million, two hundred thirty-four thousand, three hundred thirty-one".