6721067821 has 8 divisors (see below), whose sum is σ = 7392075264. Its totient is φ = 6072060720.

The previous prime is 6721067813. The next prime is 6721067887. The reversal of 6721067821 is 1287601276.

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 6721067821 - 2³ = 6721067813 is a prime.

It is a Duffinian number.

6721067821 is a modest number, since divided by 67821 gives 6721 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6721067021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5499445 + ... + 5500666.

It is an arithmetic number, because the mean of its divisors is an integer number (924009408).

Almost surely, 2^6721067821 is an apocalyptic number.

It is an amenable number.

6721067821 is a deficient number, since it is larger than the sum of its proper divisors (671007443).

6721067821 is a wasteful number, since it uses less digits than its factorization.

6721067821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11000171.

The product of its (nonzero) digits is 56448, while the sum is 40.

The square root of 6721067821 is about 81982.1189101624. The cubic root of 6721067821 is about 1887.1775402595.

The spelling of 6721067821 in words is "six billion, seven hundred twenty-one million, sixty-seven thousand, eight hundred twenty-one".