21300001321 has 4 divisors (see below), whose sum is σ = 21442954500. Its totient is φ = 21157048144.

The previous prime is 21300001297. The next prime is 21300001351. The reversal of 21300001321 is 12310000312.

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 5378608921 + 15921392400 = 73339^2 + 126180^2 .

It is a cyclic number.

It is not a de Polignac number, because 21300001321 - 2¹⁵ = 21299968553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21300001351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71476366 + ... + 71476663.

It is an arithmetic number, because the mean of its divisors is an integer number (5360738625).

Almost surely, 2^21300001321 is an apocalyptic number.

It is an amenable number.

21300001321 is a deficient number, since it is larger than the sum of its proper divisors (142953179).

21300001321 is a wasteful number, since it uses less digits than its factorization.

21300001321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142953178.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 21300001321 its reverse (12310000312), we get a palindrome (33610001633).

The spelling of 21300001321 in words is "twenty-one billion, three hundred million, one thousand, three hundred twenty-one".