21241313 has 4 divisors (see below), whose sum is σ = 22490820. Its totient is φ = 19991808.

The previous prime is 21241271. The next prime is 21241327. The reversal of 21241313 is 31314212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7573504 + 13667809 = 2752^2 + 3697^2 .

It is a cyclic number.

It is not a de Polignac number, because 21241313 - 2⁶ = 21241249 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 1249489 = 21241313 / (2 + 1 + 2 + 4 + 1 + 3 + 1 + 3).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21241291 and 21241300.

It is not an unprimeable number, because it can be changed into a prime (21241333) 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 in 3 ways as a sum of consecutive naturals, for example, 624728 + ... + 624761.

It is an arithmetic number, because the mean of its divisors is an integer number (5622705).

Almost surely, 2^21241313 is an apocalyptic number.

It is an amenable number.

21241313 is a deficient number, since it is larger than the sum of its proper divisors (1249507).

21241313 is a wasteful number, since it uses less digits than its factorization.

21241313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249506.

The product of its digits is 144, while the sum is 17.

The square root of 21241313 is about 4608.8298948866. The cubic root of 21241313 is about 276.9451641551.

Adding to 21241313 its reverse (31314212), we get a palindrome (52555525).

The spelling of 21241313 in words is "twenty-one million, two hundred forty-one thousand, three hundred thirteen".