21335313 has 4 divisors (see below), whose sum is σ = 28447088. Its totient is φ = 14223540.

The previous prime is 21335311. The next prime is 21335339. The reversal of 21335313 is 31353312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21335313 - 2¹ = 21335311 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21335313.

It is not an unprimeable number, because it can be changed into a prime (21335311) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3555883 + ... + 3555888.

It is an arithmetic number, because the mean of its divisors is an integer number (7111772).

Almost surely, 2^21335313 is an apocalyptic number.

It is an amenable number.

21335313 is a deficient number, since it is larger than the sum of its proper divisors (7111775).

21335313 is an equidigital number, since it uses as much as digits as its factorization.

21335313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7111774.

The product of its digits is 810, while the sum is 21.

The square root of 21335313 is about 4619.0164537486. The cubic root of 21335313 is about 277.3530883762.

Adding to 21335313 its reverse (31353312), we get a palindrome (52688625).

The spelling of 21335313 in words is "twenty-one million, three hundred thirty-five thousand, three hundred thirteen".