21410221 has 4 divisors (see below), whose sum is σ = 24468832. Its totient is φ = 18351612.

The previous prime is 21410219. The next prime is 21410237. The reversal of 21410221 is 12201412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21410221 - 2¹ = 21410219 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 (21410261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1529295 + ... + 1529308.

It is an arithmetic number, because the mean of its divisors is an integer number (6117208).

Almost surely, 2^21410221 is an apocalyptic number.

It is an amenable number.

21410221 is a deficient number, since it is larger than the sum of its proper divisors (3058611).

21410221 is an equidigital number, since it uses as much as digits as its factorization.

21410221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3058610.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21410221 is about 4627.1180015210. The cubic root of 21410221 is about 277.6773035673.

Adding to 21410221 its reverse (12201412), we get a palindrome (33611633).

The spelling of 21410221 in words is "twenty-one million, four hundred ten thousand, two hundred twenty-one".