6728821 has 8 divisors (see below), whose sum is σ = 7772544. Its totient is φ = 5757120.

The previous prime is 6728809. The next prime is 6728833. The reversal of 6728821 is 1288276.

It is an interprime number because it is at equal distance from previous prime (6728809) and next prime (6728833).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6728821 - 2¹¹ = 6726773 is a prime.

It is a Duffinian number.

6728821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6728801) 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 7 ways as a sum of consecutive naturals, for example, 17805 + ... + 18178.

It is an arithmetic number, because the mean of its divisors is an integer number (971568).

Almost surely, 2^6728821 is an apocalyptic number.

It is an amenable number.

6728821 is a deficient number, since it is larger than the sum of its proper divisors (1043723).

6728821 is a wasteful number, since it uses less digits than its factorization.

6728821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36011.

The product of its digits is 10752, while the sum is 34.

The square root of 6728821 is about 2593.9971087108. The cubic root of 6728821 is about 188.7902921161.

It can be divided in two parts, 6 and 728821, that added together give a palindrome (728827).

The spelling of 6728821 in words is "six million, seven hundred twenty-eight thousand, eight hundred twenty-one".