21313333 has 2 divisors, whose sum is σ = 21313334. Its totient is φ = 21313332.

The previous prime is 21313301. The next prime is 21313343. The reversal of 21313333 is 33331312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20277009 + 1036324 = 4503^2 + 1018^2 .

It is a cyclic number.

It is not a de Polignac number, because 21313333 - 2⁵ = 21313301 is a prime.

21313333 is a modest number, since divided by 3333 gives 2131 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 21313333.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21313343) 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, 10656666 + 10656667.

It is an arithmetic number, because the mean of its divisors is an integer number (10656667).

Almost surely, 2^21313333 is an apocalyptic number.

It is an amenable number.

21313333 is a deficient number, since it is larger than the sum of its proper divisors (1).

21313333 is an equidigital number, since it uses as much as digits as its factorization.

21313333 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486, while the sum is 19.

The square root of 21313333 is about 4616.6365462315. The cubic root of 21313333 is about 277.2578110370.

Adding to 21313333 its reverse (33331312), we get a palindrome (54644645).

The spelling of 21313333 in words is "twenty-one million, three hundred thirteen thousand, three hundred thirty-three".