21383633 has 2 divisors, whose sum is σ = 21383634. Its totient is φ = 21383632.

The previous prime is 21383597. The next prime is 21383651. The reversal of 21383633 is 33638312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19775809 + 1607824 = 4447^2 + 1268^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21383633 is a prime.

It is a super-3 number, since 3×21383633³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21383596 and 21383605.

It is not a weakly prime, because it can be changed into another prime (21383833) 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, 10691816 + 10691817.

It is an arithmetic number, because the mean of its divisors is an integer number (10691817).

Almost surely, 2^21383633 is an apocalyptic number.

It is an amenable number.

21383633 is a deficient number, since it is larger than the sum of its proper divisors (1).

21383633 is an equidigital number, since it uses as much as digits as its factorization.

21383633 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7776, while the sum is 29.

The square root of 21383633 is about 4624.2440463280. The cubic root of 21383633 is about 277.5623126576.

The spelling of 21383633 in words is "twenty-one million, three hundred eighty-three thousand, six hundred thirty-three".