21866041 has 2 divisors, whose sum is σ = 21866042. Its totient is φ = 21866040.

The previous prime is 21866027. The next prime is 21866057. The reversal of 21866041 is 14066812.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19616041 + 2250000 = 4429^2 + 1500^2 .

It is a cyclic number.

It is not a de Polignac number, because 21866041 - 2¹¹ = 21863993 is a prime.

It is not a weakly prime, because it can be changed into another prime (21866011) 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, 10933020 + 10933021.

It is an arithmetic number, because the mean of its divisors is an integer number (10933021).

Almost surely, 2^21866041 is an apocalyptic number.

It is an amenable number.

21866041 is a deficient number, since it is larger than the sum of its proper divisors (1).

21866041 is an equidigital number, since it uses as much as digits as its factorization.

21866041 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21866041 is about 4676.1138779974. The cubic root of 21866041 is about 279.6340499860.

The spelling of 21866041 in words is "twenty-one million, eight hundred sixty-six thousand, forty-one".