21683843 has 2 divisors, whose sum is σ = 21683844. Its totient is φ = 21683842.

The previous prime is 21683839. The next prime is 21683899. The reversal of 21683843 is 34838612.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21683843 - 2² = 21683839 is a prime.

It is not a weakly prime, because it can be changed into another prime (21683803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10841921 + 10841922.

It is an arithmetic number, because the mean of its divisors is an integer number (10841922).

Almost surely, 2^21683843 is an apocalyptic number.

21683843 is a deficient number, since it is larger than the sum of its proper divisors (1).

21683843 is an equidigital number, since it uses as much as digits as its factorization.

21683843 is an odious number, because the sum of its binary digits is odd.

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

The square root of 21683843 is about 4656.5913499039. The cubic root of 21683843 is about 278.8552025035.

The spelling of 21683843 in words is "twenty-one million, six hundred eighty-three thousand, eight hundred forty-three".