6720517 has 2 divisors, whose sum is σ = 6720518. Its totient is φ = 6720516.

The previous prime is 6720503. The next prime is 6720523. The reversal of 6720517 is 7150276.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6584356 + 136161 = 2566^2 + 369^2 .

It is a cyclic number.

It is not a de Polignac number, because 6720517 - 2¹¹ = 6718469 is a prime.

6720517 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6720617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3360258 + 3360259.

It is an arithmetic number, because the mean of its divisors is an integer number (3360259).

Almost surely, 2^6720517 is an apocalyptic number.

It is an amenable number.

6720517 is a deficient number, since it is larger than the sum of its proper divisors (1).

6720517 is an equidigital number, since it uses as much as digits as its factorization.

6720517 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2940, while the sum is 28.

The square root of 6720517 is about 2592.3959959852. The cubic root of 6720517 is about 188.7125984691.

The spelling of 6720517 in words is "six million, seven hundred twenty thousand, five hundred seventeen".