21286633 has 2 divisors, whose sum is σ = 21286634. Its totient is φ = 21286632.

The previous prime is 21286627. The next prime is 21286673. The reversal of 21286633 is 33668212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17740944 + 3545689 = 4212^2 + 1883^2 .

It is a cyclic number.

It is not a de Polignac number, because 21286633 - 2⁹ = 21286121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21286595 and 21286604.

It is not a weakly prime, because it can be changed into another prime (21286613) 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, 10643316 + 10643317.

It is an arithmetic number, because the mean of its divisors is an integer number (10643317).

Almost surely, 2^21286633 is an apocalyptic number.

It is an amenable number.

21286633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21286633 is an equidigital number, since it uses as much as digits as its factorization.

21286633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368, while the sum is 31.

The square root of 21286633 is about 4613.7439244067. The cubic root of 21286633 is about 277.1419856215.

The spelling of 21286633 in words is "twenty-one million, two hundred eighty-six thousand, six hundred thirty-three".