21321334465 has 8 divisors (see below), whose sum is σ = 27090636840. Its totient is φ = 16053710592.

The previous prime is 21321334459. The next prime is 21321334469. The reversal of 21321334465 is 56443312312.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1811949489 + 19509384976 = 42567^2 + 139676^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21321334465 - 2⁷ = 21321334337 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21321334465.

It is not an unprimeable number, because it can be changed into a prime (21321334469) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 125419530 + ... + 125419699.

It is an arithmetic number, because the mean of its divisors is an integer number (3386329605).

Almost surely, 2^21321334465 is an apocalyptic number.

It is an amenable number.

21321334465 is a deficient number, since it is larger than the sum of its proper divisors (5769302375).

21321334465 is a wasteful number, since it uses less digits than its factorization.

21321334465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250839251.

The product of its digits is 51840, while the sum is 34.

Adding to 21321334465 its reverse (56443312312), we get a palindrome (77764646777).

The spelling of 21321334465 in words is "twenty-one billion, three hundred twenty-one million, three hundred thirty-four thousand, four hundred sixty-five".