6721648745 has 12 divisors (see below), whose sum is σ = 9382873284. Its totient is φ = 4609130400.

The previous prime is 6721648711. The next prime is 6721648789. The reversal of 6721648745 is 5478461276.

It can be written as a sum of positive squares in 2 ways, for example, as 4285535296 + 2436113449 = 65464^2 + 49357^2 .

It is not a de Polignac number, because 6721648745 - 2¹⁴ = 6721632361 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6721648693 and 6721648702.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 13717406 + ... + 13717895.

It is an arithmetic number, because the mean of its divisors is an integer number (781906107).

Almost surely, 2^6721648745 is an apocalyptic number.

It is an amenable number.

6721648745 is a deficient number, since it is larger than the sum of its proper divisors (2661224539).

6721648745 is a wasteful number, since it uses less digits than its factorization.

6721648745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27435320 (or 27435313 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 50.

The square root of 6721648745 is about 81985.6618257119. The cubic root of 6721648745 is about 1887.2319103472.

The spelling of 6721648745 in words is "six billion, seven hundred twenty-one million, six hundred forty-eight thousand, seven hundred forty-five".