21001241 has 8 divisors (see below), whose sum is σ = 21500640. Its totient is φ = 20507872.

The previous prime is 21001187. The next prime is 21001247. The reversal of 21001241 is 14210012.

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 21001241 - 2⁶ = 21001177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001247) 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, 5966 + ... + 8808.

It is an arithmetic number, because the mean of its divisors is an integer number (2687580).

Almost surely, 2^21001241 is an apocalyptic number.

It is an amenable number.

21001241 is a deficient number, since it is larger than the sum of its proper divisors (499399).

21001241 is an equidigital number, since it uses as much as digits as its factorization.

21001241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3015.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21001241 is about 4582.7110971564. The cubic root of 21001241 is about 275.8978521738.

Adding to 21001241 its reverse (14210012), we get a palindrome (35211253).

The spelling of 21001241 in words is "twenty-one million, one thousand, two hundred forty-one".