21368843 has 2 divisors, whose sum is σ = 21368844. Its totient is φ = 21368842.

The previous prime is 21368821. The next prime is 21368857. The reversal of 21368843 is 34886312.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21368843 - 2¹² = 21364747 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21368803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10684421 + 10684422.

It is an arithmetic number, because the mean of its divisors is an integer number (10684422).

Almost surely, 2^21368843 is an apocalyptic number.

21368843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21368843 is an equidigital number, since it uses as much as digits as its factorization.

21368843 is an evil number, because the sum of its binary digits is even.

The product of its digits is 27648, while the sum is 35.

The square root of 21368843 is about 4622.6445894098. The cubic root of 21368843 is about 277.4983058631.

The spelling of 21368843 in words is "twenty-one million, three hundred sixty-eight thousand, eight hundred forty-three".