21843953 has 2 divisors, whose sum is σ = 21843954. Its totient is φ = 21843952.

The previous prime is 21843937. The next prime is 21843979. The reversal of 21843953 is 35934812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11235904 + 10608049 = 3352^2 + 3257^2 .

It is a cyclic number.

It is not a de Polignac number, because 21843953 - 2⁴ = 21843937 is a prime.

It is not a weakly prime, because it can be changed into another prime (21843923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10921976 + 10921977.

It is an arithmetic number, because the mean of its divisors is an integer number (10921977).

Almost surely, 2^21843953 is an apocalyptic number.

It is an amenable number.

21843953 is a deficient number, since it is larger than the sum of its proper divisors (1).

21843953 is an equidigital number, since it uses as much as digits as its factorization.

21843953 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 35.

The square root of 21843953 is about 4673.7514910401. The cubic root of 21843953 is about 279.5398607389.

The spelling of 21843953 in words is "twenty-one million, eight hundred forty-three thousand, nine hundred fifty-three".