21013303 has 2 divisors, whose sum is σ = 21013304. Its totient is φ = 21013302.

The previous prime is 21013301. The next prime is 21013357. The reversal of 21013303 is 30331012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21013303 - 2¹ = 21013301 is a prime.

Together with 21013301, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21013301) 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, 10506651 + 10506652.

It is an arithmetic number, because the mean of its divisors is an integer number (10506652).

Almost surely, 2^21013303 is an apocalyptic number.

21013303 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013303 is an equidigital number, since it uses as much as digits as its factorization.

21013303 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 54, while the sum is 13.

The square root of 21013303 is about 4584.0269414566. The cubic root of 21013303 is about 275.9506624335.

Adding to 21013303 its reverse (30331012), we get a palindrome (51344315).

It can be divided in two parts, 21013 and 303, that added together give a square (21316 = 146²).

The spelling of 21013303 in words is "twenty-one million, thirteen thousand, three hundred three".