717987 has 4 divisors (see below), whose sum is σ = 957320. Its totient is φ = 478656.

The previous prime is 717979. The next prime is 717989. The reversal of 717987 is 789717.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 789717 = 3 ⋅263239.

It is not a de Polignac number, because 717987 - 2³ = 717979 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (717989) 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 in 3 ways as a sum of consecutive naturals, for example, 119662 + ... + 119667.

It is an arithmetic number, because the mean of its divisors is an integer number (239330).

2⁷¹⁷⁹⁸⁷ is an apocalyptic number.

717987 is a deficient number, since it is larger than the sum of its proper divisors (239333).

717987 is a wasteful number, since it uses less digits than its factorization.

717987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239332.

The product of its digits is 24696, while the sum is 39.

The square root of 717987 is about 847.3411355529. The cubic root of 717987 is about 89.5444885610.

The spelling of 717987 in words is "seven hundred seventeen thousand, nine hundred eighty-seven".