6607721 has 2 divisors, whose sum is σ = 6607722. Its totient is φ = 6607720.

The previous prime is 6607717. The next prime is 6607729. The reversal of 6607721 is 1277066.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5017600 + 1590121 = 2240^2 + 1261^2 .

It is a cyclic number.

It is not a de Polignac number, because 6607721 - 2² = 6607717 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6607729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3303860 + 3303861.

It is an arithmetic number, because the mean of its divisors is an integer number (3303861).

Almost surely, 2^6607721 is an apocalyptic number.

It is an amenable number.

6607721 is a deficient number, since it is larger than the sum of its proper divisors (1).

6607721 is an equidigital number, since it uses as much as digits as its factorization.

6607721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 29.

The square root of 6607721 is about 2570.5487740947. The cubic root of 6607721 is about 187.6508628792.

The spelling of 6607721 in words is "six million, six hundred seven thousand, seven hundred twenty-one".