21400334321 has 4 divisors (see below), whose sum is σ = 21409903092. Its totient is φ = 21390765552.

The previous prime is 21400334317. The next prime is 21400334323. The reversal of 21400334321 is 12343300412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10467540721 + 10932793600 = 102311^2 + 104560^2 .

It is a cyclic number.

It is not a de Polignac number, because 21400334321 - 2² = 21400334317 is a prime.

It is a super-3 number, since 3×21400334321³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21400334323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4781030 + ... + 4785503.

It is an arithmetic number, because the mean of its divisors is an integer number (5352475773).

Almost surely, 2^21400334321 is an apocalyptic number.

It is an amenable number.

21400334321 is a deficient number, since it is larger than the sum of its proper divisors (9568771).

21400334321 is an equidigital number, since it uses as much as digits as its factorization.

21400334321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9568770.

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21400334321 its reverse (12343300412), we get a palindrome (33743634733).

The spelling of 21400334321 in words is "twenty-one billion, four hundred million, three hundred thirty-four thousand, three hundred twenty-one".