21660355644311 has 4 divisors (see below), whose sum is σ = 21957072844992. Its totient is φ = 21363638443632.

The previous prime is 21660355644293. The next prime is 21660355644379. The reversal of 21660355644311 is 11344655306612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21660355644311 - 2¹⁰ = 21660355643287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21660355644611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148358600231 + ... + 148358600376.

It is an arithmetic number, because the mean of its divisors is an integer number (5489268211248).

Almost surely, 2^{21660355644311} is an apocalyptic number.

21660355644311 is a deficient number, since it is larger than the sum of its proper divisors (296717200681).

21660355644311 is an equidigital number, since it uses as much as digits as its factorization.

21660355644311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296717200680.

The product of its (nonzero) digits is 1555200, while the sum is 47.

The spelling of 21660355644311 in words is "twenty-one trillion, six hundred sixty billion, three hundred fifty-five million, six hundred forty-four thousand, three hundred eleven".