21660411454105 has 4 divisors (see below), whose sum is σ = 25992493744932. Its totient is φ = 17328329163280.

The previous prime is 21660411454091. The next prime is 21660411454127. The reversal of 21660411454105 is 50145411406612.

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 12684731002969 + 8975680451136 = 3561563^2 + 2995944^2 .

It is not a de Polignac number, because 21660411454105 - 2²¹ = 21660409356953 is a prime.

It is a super-2 number, since 2×21660411454105² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2166041145406 + ... + 2166041145415.

It is an arithmetic number, because the mean of its divisors is an integer number (6498123436233).

Almost surely, 2^{21660411454105} is an apocalyptic number.

It is an amenable number.

21660411454105 is a deficient number, since it is larger than the sum of its proper divisors (4332082290827).

21660411454105 is an equidigital number, since it uses as much as digits as its factorization.

21660411454105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4332082290826.

The product of its (nonzero) digits is 115200, while the sum is 40.

The spelling of 21660411454105 in words is "twenty-one trillion, six hundred sixty billion, four hundred eleven million, four hundred fifty-four thousand, one hundred five".