720680669 has 2 divisors, whose sum is σ = 720680670. Its totient is φ = 720680668.

The previous prime is 720680647. The next prime is 720680687. The reversal of 720680669 is 966086027.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 558755044 + 161925625 = 23638^2 + 12725^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-720680669 is a prime.

It is a super-2 number, since 2×720680669² = 1038761253340575122, which contains 22 as substring.

It is a Chen prime.

It is equal to p_37267586 and since 720680669 and 37267586 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (720680629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360340334 + 360340335.

It is an arithmetic number, because the mean of its divisors is an integer number (360340335).

Almost surely, 2^720680669 is an apocalyptic number.

It is an amenable number.

720680669 is a deficient number, since it is larger than the sum of its proper divisors (1).

720680669 is an equidigital number, since it uses as much as digits as its factorization.

720680669 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 720680669 is about 26845.4962516993. The cubic root of 720680669 is about 896.5633004735.

The spelling of 720680669 in words is "seven hundred twenty million, six hundred eighty thousand, six hundred sixty-nine".