21270241 has 4 divisors (see below), whose sum is σ = 21281584. Its totient is φ = 21258900.

The previous prime is 21270233. The next prime is 21270269. The reversal of 21270241 is 14207212.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21270241 - 2³ = 21270233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21270941) 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, 2115 + ... + 6856.

It is an arithmetic number, because the mean of its divisors is an integer number (5320396).

Almost surely, 2^21270241 is an apocalyptic number.

It is an amenable number.

21270241 is a deficient number, since it is larger than the sum of its proper divisors (11343).

21270241 is an equidigital number, since it uses as much as digits as its factorization.

21270241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11342.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21270241 is about 4611.9671507937. The cubic root of 21270241 is about 277.0708286340.

Adding to 21270241 its reverse (14207212), we get a palindrome (35477453).

The spelling of 21270241 in words is "twenty-one million, two hundred seventy thousand, two hundred forty-one".