21144241 has 4 divisors (see below), whose sum is σ = 21220852. Its totient is φ = 21067632.

The previous prime is 21144229. The next prime is 21144259. The reversal of 21144241 is 14244112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4161600 + 16982641 = 2040^2 + 4121^2 .

It is a cyclic number.

It is not a de Polignac number, because 21144241 - 2¹⁵ = 21111473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21144341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37890 + ... + 38443.

It is an arithmetic number, because the mean of its divisors is an integer number (5305213).

Almost surely, 2^21144241 is an apocalyptic number.

It is an amenable number.

21144241 is a deficient number, since it is larger than the sum of its proper divisors (76611).

21144241 is an equidigital number, since it uses as much as digits as its factorization.

21144241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76610.

The product of its digits is 256, while the sum is 19.

The square root of 21144241 is about 4598.2867461697. The cubic root of 21144241 is about 276.5226435441.

Adding to 21144241 its reverse (14244112), we get a palindrome (35388353).

The spelling of 21144241 in words is "twenty-one million, one hundred forty-four thousand, two hundred forty-one".