21242441 has 8 divisors (see below), whose sum is σ = 23212224. Its totient is φ = 19279120.

The previous prime is 21242393. The next prime is 21242443. The reversal of 21242441 is 14424212.

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 21242441 - 2²² = 17048137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21242443) 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, 7556 + ... + 9978.

It is an arithmetic number, because the mean of its divisors is an integer number (2901528).

Almost surely, 2^21242441 is an apocalyptic number.

It is an amenable number.

21242441 is a deficient number, since it is larger than the sum of its proper divisors (1969783).

21242441 is a wasteful number, since it uses less digits than its factorization.

21242441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3231.

The product of its digits is 512, while the sum is 20.

The square root of 21242441 is about 4608.9522670559. The cubic root of 21242441 is about 276.9500663727.

Adding to 21242441 its reverse (14424212), we get a palindrome (35666653).

The spelling of 21242441 in words is "twenty-one million, two hundred forty-two thousand, four hundred forty-one".