721680677 has 2 divisors, whose sum is σ = 721680678. Its totient is φ = 721680676.

The previous prime is 721680611. The next prime is 721680709. The reversal of 721680677 is 776086127.

721680677 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 529276036 + 192404641 = 23006^2 + 13871^2 .

It is an emirp because it is prime and its reverse (776086127) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 721680677 - 2¹⁰ = 721679653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (721686677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 360840338 + 360840339.

It is an arithmetic number, because the mean of its divisors is an integer number (360840339).

Almost surely, 2^721680677 is an apocalyptic number.

It is an amenable number.

721680677 is a deficient number, since it is larger than the sum of its proper divisors (1).

721680677 is an equidigital number, since it uses as much as digits as its factorization.

721680677 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 197568, while the sum is 44.

The square root of 721680677 is about 26864.1150421896. The cubic root of 721680677 is about 896.9777957050.

The spelling of 721680677 in words is "seven hundred twenty-one million, six hundred eighty thousand, six hundred seventy-seven".