21212033 has 2 divisors, whose sum is σ = 21212034. Its totient is φ = 21212032.

The previous prime is 21212017. The next prime is 21212071. The reversal of 21212033 is 33021212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13965169 + 7246864 = 3737^2 + 2692^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212033 - 2⁴ = 21212017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211999 and 21212017.

It is not a weakly prime, because it can be changed into another prime (21212083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606016 + 10606017.

It is an arithmetic number, because the mean of its divisors is an integer number (10606017).

Almost surely, 2^21212033 is an apocalyptic number.

It is an amenable number.

21212033 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212033 is an equidigital number, since it uses as much as digits as its factorization.

21212033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21212033 is about 4605.6522882215. The cubic root of 21212033 is about 276.8178543355.

Adding to 21212033 its reverse (33021212), we get a palindrome (54233245).

The spelling of 21212033 in words is "twenty-one million, two hundred twelve thousand, thirty-three".