21413313 has 12 divisors (see below), whose sum is σ = 31237908. Its totient is φ = 14133600.

The previous prime is 21413303. The next prime is 21413369. The reversal of 21413313 is 31331412.

It can be written as a sum of positive squares in 2 ways, for example, as 9072144 + 12341169 = 3012^2 + 3513^2 .

It is not a de Polignac number, because 21413313 - 2⁴ = 21413297 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21413303) 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 11 ways as a sum of consecutive naturals, for example, 10870 + ... + 12687.

It is an arithmetic number, because the mean of its divisors is an integer number (2603159).

Almost surely, 2^21413313 is an apocalyptic number.

It is an amenable number.

21413313 is a deficient number, since it is larger than the sum of its proper divisors (9824595).

21413313 is a wasteful number, since it uses less digits than its factorization.

21413313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23664 (or 23661 counting only the distinct ones).

The product of its digits is 216, while the sum is 18.

The square root of 21413313 is about 4627.4521067214. The cubic root of 21413313 is about 277.6906700321.

Adding to 21413313 its reverse (31331412), we get a palindrome (52744725).

The spelling of 21413313 in words is "twenty-one million, four hundred thirteen thousand, three hundred thirteen".