21376604663017 has 4 divisors (see below), whose sum is σ = 21897985264596. Its totient is φ = 20855224061440.

The previous prime is 21376604662939. The next prime is 21376604663033. The reversal of 21376604663017 is 71036640667312.

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 3629771798416 + 17746832864601 = 1905196^2 + 4212699^2 .

It is a cyclic number.

It is not a de Polignac number, because 21376604663017 - 2¹¹ = 21376604660969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21376604666017) 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, 260690300728 + ... + 260690300809.

It is an arithmetic number, because the mean of its divisors is an integer number (5474496316149).

Almost surely, 2^{21376604663017} is an apocalyptic number.

It is an amenable number.

21376604663017 is a deficient number, since it is larger than the sum of its proper divisors (521380601579).

21376604663017 is an equidigital number, since it uses as much as digits as its factorization.

21376604663017 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521380601578.

The product of its (nonzero) digits is 4572288, while the sum is 52.

The spelling of 21376604663017 in words is "twenty-one trillion, three hundred seventy-six billion, six hundred four million, six hundred sixty-three thousand, seventeen".