21535433 has 2 divisors, whose sum is σ = 21535434. Its totient is φ = 21535432.

The previous prime is 21535411. The next prime is 21535477. The reversal of 21535433 is 33453512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14417209 + 7118224 = 3797^2 + 2668^2 .

It is a cyclic number.

It is not a de Polignac number, because 21535433 - 2¹² = 21531337 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21535403) 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, 10767716 + 10767717.

It is an arithmetic number, because the mean of its divisors is an integer number (10767717).

Almost surely, 2^21535433 is an apocalyptic number.

It is an amenable number.

21535433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21535433 is an equidigital number, since it uses as much as digits as its factorization.

21535433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 26.

The square root of 21535433 is about 4640.6285134667. The cubic root of 21535433 is about 278.2175591103.

Adding to 21535433 its reverse (33453512), we get a palindrome (54988945).

The spelling of 21535433 in words is "twenty-one million, five hundred thirty-five thousand, four hundred thirty-three".