21320443506353 has 8 divisors (see below), whose sum is σ = 21366158123520. Its totient is φ = 21274757818720.

The previous prime is 21320443506319. The next prime is 21320443506359. The reversal of 21320443506353 is 35360534402312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21320443506353 - 2²⁰ = 21320442457777 is a prime.

It is a super-3 number, since 3×21320443506353³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21320443506353.

It is not an unprimeable number, because it can be changed into a prime (21320443506359) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5756525 + ... + 8705082.

It is an arithmetic number, because the mean of its divisors is an integer number (2670769765440).

Almost surely, 2^{21320443506353} is an apocalyptic number.

It is an amenable number.

21320443506353 is a deficient number, since it is larger than the sum of its proper divisors (45714617167).

21320443506353 is a wasteful number, since it uses less digits than its factorization.

21320443506353 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14464767.

The product of its (nonzero) digits is 777600, while the sum is 41.

Adding to 21320443506353 its reverse (35360534402312), we get a palindrome (56680977908665).

The spelling of 21320443506353 in words is "twenty-one trillion, three hundred twenty billion, four hundred forty-three million, five hundred six thousand, three hundred fifty-three".