21310300321 has 4 divisors (see below), whose sum is σ = 21313190212. Its totient is φ = 21307410432.

The previous prime is 21310300301. The next prime is 21310300339. The reversal of 21310300321 is 12300301312.

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 4467451921 + 16842848400 = 66839^2 + 129780^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21310300321 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21310300295 and 21310300304.

It is not an unprimeable number, because it can be changed into a prime (21310300301) 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, 1433856 + ... + 1448641.

It is an arithmetic number, because the mean of its divisors is an integer number (5328297553).

Almost surely, 2^21310300321 is an apocalyptic number.

It is an amenable number.

21310300321 is a deficient number, since it is larger than the sum of its proper divisors (2889891).

21310300321 is an equidigital number, since it uses as much as digits as its factorization.

21310300321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2889890.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21310300321 its reverse (12300301312), we get a palindrome (33610601633).

Subtracting from 21310300321 its reverse (12300301312), we obtain a palindrome (9009999009).

The spelling of 21310300321 in words is "twenty-one billion, three hundred ten million, three hundred thousand, three hundred twenty-one".