21321344343265 has 4 divisors (see below), whose sum is σ = 25585613211924. Its totient is φ = 17057075474608.

The previous prime is 21321344343251. The next prime is 21321344343293. The reversal of 21321344343265 is 56234344312312.

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 2794035942369 + 18527308400896 = 1671537^2 + 4304336^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321344343265 - 2¹¹ = 21321344341217 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2132134434322 + ... + 2132134434331.

It is an arithmetic number, because the mean of its divisors is an integer number (6396403302981).

Almost surely, 2^{21321344343265} is an apocalyptic number.

It is an amenable number.

21321344343265 is a deficient number, since it is larger than the sum of its proper divisors (4264268868659).

21321344343265 is an equidigital number, since it uses as much as digits as its factorization.

21321344343265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4264268868658.

The product of its digits is 1244160, while the sum is 43.

Adding to 21321344343265 its reverse (56234344312312), we get a palindrome (77555688655577).

The spelling of 21321344343265 in words is "twenty-one trillion, three hundred twenty-one billion, three hundred forty-four million, three hundred forty-three thousand, two hundred sixty-five".