21653436313 has 4 divisors (see below), whose sum is σ = 22181568948. Its totient is φ = 21125303680.

The previous prime is 21653436289. The next prime is 21653436323. The reversal of 21653436313 is 31363435612.

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 2532907584 + 19120528729 = 50328^2 + 138277^2 .

It is a cyclic number.

It is not a de Polignac number, because 21653436313 - 2⁵ = 21653436281 is a prime.

It is a super-2 number, since 2×21653436313² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21653436323) 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, 264066256 + ... + 264066337.

It is an arithmetic number, because the mean of its divisors is an integer number (5545392237).

Almost surely, 2^21653436313 is an apocalyptic number.

It is an amenable number.

21653436313 is a deficient number, since it is larger than the sum of its proper divisors (528132635).

21653436313 is an equidigital number, since it uses as much as digits as its factorization.

21653436313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528132634.

The product of its digits is 116640, while the sum is 37.

The spelling of 21653436313 in words is "twenty-one billion, six hundred fifty-three million, four hundred thirty-six thousand, three hundred thirteen".