917989 has 8 divisors (see below), whose sum is σ = 948600. Its totient is φ = 888000.

The previous prime is 917971. The next prime is 917993. The reversal of 917989 is 989719.

It can be written as a sum of positive squares in 4 ways, for example, as 24964 + 893025 = 158^2 + 945^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-917989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (917089) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6087 + ... + 6235.

It is an arithmetic number, because the mean of its divisors is an integer number (118575).

2⁹¹⁷⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

917989 is a deficient number, since it is larger than the sum of its proper divisors (30611).

917989 is a wasteful number, since it uses less digits than its factorization.

917989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311.

The product of its digits is 40824, while the sum is 43.

The square root of 917989 is about 958.1174249537. The cubic root of 917989 is about 97.1879658480.

The spelling of 917989 in words is "nine hundred seventeen thousand, nine hundred eighty-nine".