21043441 has 2 divisors, whose sum is σ = 21043442. Its totient is φ = 21043440.

The previous prime is 21043423. The next prime is 21043453. The reversal of 21043441 is 14434012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11458225 + 9585216 = 3385^2 + 3096^2 .

It is a cyclic number.

It is not a de Polignac number, because 21043441 - 2⁵ = 21043409 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21043481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10521720 + 10521721.

It is an arithmetic number, because the mean of its divisors is an integer number (10521721).

Almost surely, 2^21043441 is an apocalyptic number.

It is an amenable number.

21043441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21043441 is an equidigital number, since it uses as much as digits as its factorization.

21043441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21043441 is about 4587.3130479617. The cubic root of 21043441 is about 276.0825253815.

Adding to 21043441 its reverse (14434012), we get a palindrome (35477453).

The spelling of 21043441 in words is "twenty-one million, forty-three thousand, four hundred forty-one".