6721678641 has 8 divisors (see below), whose sum is σ = 8963264800. Its totient is φ = 4480605792.

The previous prime is 6721678627. The next prime is 6721678643. The reversal of 6721678641 is 1468761276.

6721678641 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 6721678641 - 2¹¹ = 6721676593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6721678643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 96655 + ... + 150948.

It is an arithmetic number, because the mean of its divisors is an integer number (1120408100).

Almost surely, 2^6721678641 is an apocalyptic number.

It is an amenable number.

6721678641 is a deficient number, since it is larger than the sum of its proper divisors (2241586159).

6721678641 is a wasteful number, since it uses less digits than its factorization.

6721678641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256655.

The product of its digits is 677376, while the sum is 48.

The square root of 6721678641 is about 81985.8441500726. The cubic root of 6721678641 is about 1887.2347083017.

The spelling of 6721678641 in words is "six billion, seven hundred twenty-one million, six hundred seventy-eight thousand, six hundred forty-one".