21411305 has 8 divisors (see below), whose sum is σ = 26115144. Its totient is φ = 16848000.

The previous prime is 21411301. The next prime is 21411317. The reversal of 21411305 is 50311412.

It can be written as a sum of positive squares in 4 ways, for example, as 1008016 + 20403289 = 1004^2 + 4517^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21411305 - 2² = 21411301 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21411301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34796 + ... + 35405.

It is an arithmetic number, because the mean of its divisors is an integer number (3264393).

Almost surely, 2^21411305 is an apocalyptic number.

It is an amenable number.

21411305 is a deficient number, since it is larger than the sum of its proper divisors (4703839).

21411305 is an equidigital number, since it uses as much as digits as its factorization.

21411305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70267.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 21411305 is about 4627.2351355858. The cubic root of 21411305 is about 277.6819897577.

Adding to 21411305 its reverse (50311412), we get a palindrome (71722717).

The spelling of 21411305 in words is "twenty-one million, four hundred eleven thousand, three hundred five".