21313303 has 16 divisors (see below), whose sum is σ = 23892480. Its totient is φ = 19006680.

The previous prime is 21313301. The next prime is 21313333. The reversal of 21313303 is 30331312.

It is not a de Polignac number, because 21313303 - 2¹ = 21313301 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313301) 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 in 15 ways as a sum of consecutive naturals, for example, 89058 + ... + 89296.

It is an arithmetic number, because the mean of its divisors is an integer number (1493280).

Almost surely, 2^21313303 is an apocalyptic number.

21313303 is a deficient number, since it is larger than the sum of its proper divisors (2579177).

21313303 is an equidigital number, since it uses as much as digits as its factorization.

21313303 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 162, while the sum is 16.

The square root of 21313303 is about 4616.6332971117. The cubic root of 21313303 is about 277.2576809504.

Adding to 21313303 its reverse (30331312), we get a palindrome (51644615).

Subtracting 21313303 from its reverse (30331312), we obtain a square (9018009 = 3003²).

The spelling of 21313303 in words is "twenty-one million, three hundred thirteen thousand, three hundred three".