21241241 has 4 divisors (see below), whose sum is σ = 24275712. Its totient is φ = 18206772.

The previous prime is 21241229. The next prime is 21241247. The reversal of 21241241 is 14214212.

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 a de Polignac number, because none of the positive numbers 2^k-21241241 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21241247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1517225 + ... + 1517238.

It is an arithmetic number, because the mean of its divisors is an integer number (6068928).

Almost surely, 2^21241241 is an apocalyptic number.

It is an amenable number.

21241241 is a deficient number, since it is larger than the sum of its proper divisors (3034471).

21241241 is an equidigital number, since it uses as much as digits as its factorization.

21241241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3034470.

The product of its digits is 128, while the sum is 17.

The square root of 21241241 is about 4608.8220837867. The cubic root of 21241241 is about 276.9448512417.

Adding to 21241241 its reverse (14214212), we get a palindrome (35455453).

The spelling of 21241241 in words is "twenty-one million, two hundred forty-one thousand, two hundred forty-one".