21115500065005 has 8 divisors (see below), whose sum is σ = 25342263355032. Its totient is φ = 16889957867328.

The previous prime is 21115500064943. The next prime is 21115500065041. The reversal of 21115500065005 is 50056000551112.

It can be written as a sum of positive squares in 4 ways, for example, as 5265753646729 + 15849746418276 = 2294723^2 + 3981174^2 .

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 21115500065005 - 2⁷ = 21115500064877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 305235042 + ... + 305304211.

It is an arithmetic number, because the mean of its divisors is an integer number (3167782919379).

Almost surely, 2^{21115500065005} is an apocalyptic number.

It is an amenable number.

21115500065005 is a deficient number, since it is larger than the sum of its proper divisors (4226763290027).

21115500065005 is an equidigital number, since it uses as much as digits as its factorization.

21115500065005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610546175.

The product of its (nonzero) digits is 7500, while the sum is 31.

The spelling of 21115500065005 in words is "twenty-one trillion, one hundred fifteen billion, five hundred million, sixty-five thousand, five".