6756721 has 2 divisors, whose sum is σ = 6756722. Its totient is φ = 6756720.

The previous prime is 6756709. The next prime is 6756817. The reversal of 6756721 is 1276576.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5880625 + 876096 = 2425^2 + 936^2 .

It is a cyclic number.

It is not a de Polignac number, because 6756721 - 2⁵ = 6756689 is a prime.

It is not a weakly prime, because it can be changed into another prime (6756521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3378360 + 3378361.

It is an arithmetic number, because the mean of its divisors is an integer number (3378361).

Almost surely, 2^6756721 is an apocalyptic number.

It is an amenable number.

6756721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6756721 is an equidigital number, since it uses as much as digits as its factorization.

6756721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17640, while the sum is 34.

The square root of 6756721 is about 2599.3693465916. The cubic root of 6756721 is about 189.0508620799.

It can be divided in two parts, 675 and 6721, that added together give a square (7396 = 86²).

The spelling of 6756721 in words is "six million, seven hundred fifty-six thousand, seven hundred twenty-one".