6721768857 has 16 divisors (see below), whose sum is σ = 9284040000. Its totient is φ = 4320759744.

The previous prime is 6721768849. The next prime is 6721768897. The reversal of 6721768857 is 7588671276.

It is not a de Polignac number, because 6721768857 - 2³ = 6721768849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6721768797 and 6721768806.

It is not an unprimeable number, because it can be changed into a prime (6721768847) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12019 + ... + 116567.

It is an arithmetic number, because the mean of its divisors is an integer number (580252500).

Almost surely, 2^6721768857 is an apocalyptic number.

It is an amenable number.

6721768857 is a deficient number, since it is larger than the sum of its proper divisors (2562271143).

6721768857 is a wasteful number, since it uses less digits than its factorization.

6721768857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105320.

The product of its digits is 7902720, while the sum is 57.

The square root of 6721768857 is about 81986.3943407685. The cubic root of 6721768857 is about 1887.2431515301.

The spelling of 6721768857 in words is "six billion, seven hundred twenty-one million, seven hundred sixty-eight thousand, eight hundred fifty-seven".