916989 has 4 divisors (see below), whose sum is σ = 1222656. Its totient is φ = 611324.

The previous prime is 916973. The next prime is 916999. The reversal of 916989 is 989619.

916989 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 989619 = 3 ⋅329873.

It is a cyclic number.

It is not a de Polignac number, because 916989 - 2⁴ = 916973 is a prime.

It is a super-2 number, since 2×916989² = 1681737652242, which contains 22 as substring.

It is an Ulam number.

It is a D-number.

916989 is an undulating number in base 16.

916989 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 916989.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 916989.

It is not an unprimeable number, because it can be changed into a prime (916939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 152829 + ... + 152834.

It is an arithmetic number, because the mean of its divisors is an integer number (305664).

2⁹¹⁶⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

916989 is a deficient number, since it is larger than the sum of its proper divisors (305667).

916989 is a wasteful number, since it uses less digits than its factorization.

916989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305666.

The product of its digits is 34992, while the sum is 42.

The square root of 916989 is about 957.5954260542. The cubic root of 916989 is about 97.1526628551.

The spelling of 916989 in words is "nine hundred sixteen thousand, nine hundred eighty-nine".