21833552016721 has 4 divisors (see below), whose sum is σ = 21833564152500. Its totient is φ = 21833539880944.

The previous prime is 21833552016713. The next prime is 21833552016733. The reversal of 21833552016721 is 12761025533812.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19560814863121 + 2272737153600 = 4422761^2 + 1507560^2 .

It is a cyclic number.

It is not a de Polignac number, because 21833552016721 - 2³ = 21833552016713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21833550016721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2772766 + ... + 7166263.

It is an arithmetic number, because the mean of its divisors is an integer number (5458391038125).

Almost surely, 2^{21833552016721} is an apocalyptic number.

It is an amenable number.

21833552016721 is a deficient number, since it is larger than the sum of its proper divisors (12135779).

21833552016721 is an equidigital number, since it uses as much as digits as its factorization.

21833552016721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12135778.

The product of its (nonzero) digits is 604800, while the sum is 46.

The spelling of 21833552016721 in words is "twenty-one trillion, eight hundred thirty-three billion, five hundred fifty-two million, sixteen thousand, seven hundred twenty-one".