909989 has 4 divisors (see below), whose sum is σ = 918156. Its totient is φ = 901824.

The previous prime is 909977. The next prime is 910003. The reversal of 909989 is 989909.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 293764 + 616225 = 542^2 + 785^2 .

It is a cyclic number.

It is not a de Polignac number, because 909989 - 2⁴ = 909973 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 (909089) 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, 3914 + ... + 4139.

It is an arithmetic number, because the mean of its divisors is an integer number (229539).

2⁹⁰⁹⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

909989 is a deficient number, since it is larger than the sum of its proper divisors (8167).

909989 is a wasteful number, since it uses less digits than its factorization.

909989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8166.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 909989 is about 953.9334358329. The cubic root of 909989 is about 96.9048203722.

The spelling of 909989 in words is "nine hundred nine thousand, nine hundred eighty-nine".