6721313 has 4 divisors (see below), whose sum is σ = 7013568. Its totient is φ = 6429060.

The previous prime is 6721303. The next prime is 6721331. The reversal of 6721313 is 3131276.

It is a happy number.

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 a cyclic number.

It is not a de Polignac number, because 6721313 - 2¹⁰ = 6720289 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 292231 = 6721313 / (6 + 7 + 2 + 1 + 3 + 1 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6721303) 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, 146093 + ... + 146138.

It is an arithmetic number, because the mean of its divisors is an integer number (1753392).

Almost surely, 2^6721313 is an apocalyptic number.

It is an amenable number.

6721313 is a deficient number, since it is larger than the sum of its proper divisors (292255).

6721313 is a wasteful number, since it uses less digits than its factorization.

6721313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292254.

The product of its digits is 756, while the sum is 23.

The square root of 6721313 is about 2592.5495173670. The cubic root of 6721313 is about 188.7200487539.

Adding to 6721313 its reverse (3131276), we get a palindrome (9852589).

The spelling of 6721313 in words is "six million, seven hundred twenty-one thousand, three hundred thirteen".