21843923 has 2 divisors, whose sum is σ = 21843924. Its totient is φ = 21843922.

The previous prime is 21843919. The next prime is 21843937. The reversal of 21843923 is 32934812.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21843923 - 2² = 21843919 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21843923.

It is not a weakly prime, because it can be changed into another prime (21843953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10921961 + 10921962.

It is an arithmetic number, because the mean of its divisors is an integer number (10921962).

Almost surely, 2^21843923 is an apocalyptic number.

21843923 is a deficient number, since it is larger than the sum of its proper divisors (1).

21843923 is an equidigital number, since it uses as much as digits as its factorization.

21843923 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 32.

The square root of 21843923 is about 4673.7482816258. The cubic root of 21843923 is about 279.5397327676.

The spelling of 21843923 in words is "twenty-one million, eight hundred forty-three thousand, nine hundred twenty-three".