21042241 has 8 divisors (see below), whose sum is σ = 23124384. Its totient is φ = 18988320.

The previous prime is 21042223. The next prime is 21042251. The reversal of 21042241 is 14224012.

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

It is a cyclic number.

It is not a de Polignac number, because 21042241 - 2²³ = 12653633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21042251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5475 + ... + 8488.

It is an arithmetic number, because the mean of its divisors is an integer number (2890548).

Almost surely, 2^21042241 is an apocalyptic number.

It is an amenable number.

21042241 is a deficient number, since it is larger than the sum of its proper divisors (2082143).

21042241 is a wasteful number, since it uses less digits than its factorization.

21042241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14111.

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 21042241 is about 4587.1822505761. The cubic root of 21042241 is about 276.0772774228.

Adding to 21042241 its reverse (14224012), we get a palindrome (35266253).

The spelling of 21042241 in words is "twenty-one million, forty-two thousand, two hundred forty-one".