717989 has 2 divisors, whose sum is σ = 717990. Its totient is φ = 717988.

The previous prime is 717979. The next prime is 718007. The reversal of 717989 is 989717.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 708964 + 9025 = 842^2 + 95^2 .

It is a cyclic number.

It is not a de Polignac number, because 717989 - 2¹⁶ = 652453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (717919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 358994 + 358995.

It is an arithmetic number, because the mean of its divisors is an integer number (358995).

2⁷¹⁷⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

717989 is a deficient number, since it is larger than the sum of its proper divisors (1).

717989 is an equidigital number, since it uses as much as digits as its factorization.

717989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31752, while the sum is 41.

The square root of 717989 is about 847.3423157143. The cubic root of 717989 is about 89.5445717050.

The spelling of 717989 in words is "seven hundred seventeen thousand, nine hundred eighty-nine".