21104843 has 2 divisors, whose sum is σ = 21104844. Its totient is φ = 21104842.

The previous prime is 21104819. The next prime is 21104849. The reversal of 21104843 is 34840112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21104843 - 2¹⁶ = 21039307 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21104849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10552421 + 10552422.

It is an arithmetic number, because the mean of its divisors is an integer number (10552422).

Almost surely, 2^21104843 is an apocalyptic number.

21104843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21104843 is an equidigital number, since it uses as much as digits as its factorization.

21104843 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 21104843 is about 4594.0007618632. Note that the first 3 decimals coincide. The cubic root of 21104843 is about 276.3507888273.

Adding to 21104843 its reverse (34840112), we get a palindrome (55944955).

The spelling of 21104843 in words is "twenty-one million, one hundred four thousand, eight hundred forty-three".