21307333 has 2 divisors, whose sum is σ = 21307334. Its totient is φ = 21307332.

The previous prime is 21307283. The next prime is 21307339. The reversal of 21307333 is 33370312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20493729 + 813604 = 4527^2 + 902^2 .

It is a cyclic number.

It is not a de Polignac number, because 21307333 - 2¹³ = 21299141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21307339) 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, 10653666 + 10653667.

It is an arithmetic number, because the mean of its divisors is an integer number (10653667).

Almost surely, 2^21307333 is an apocalyptic number.

It is an amenable number.

21307333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21307333 is an equidigital number, since it uses as much as digits as its factorization.

21307333 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1134, while the sum is 22.

The square root of 21307333 is about 4615.9866767572. The cubic root of 21307333 is about 277.2317912838.

Adding to 21307333 its reverse (33370312), we get a palindrome (54677645).

The spelling of 21307333 in words is "twenty-one million, three hundred seven thousand, three hundred thirty-three".