1099989 has 24 divisors (see below), whose sum is σ = 1782144. Its totient is φ = 648000.

The previous prime is 1099961. The next prime is 1099997. The reversal of 1099989 is 9899901.

It is not a de Polignac number, because 1099989 - 2⁵ = 1099957 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1099289) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3924 + ... + 4194.

It is an arithmetic number, because the mean of its divisors is an integer number (74256).

2^1099989 is an apocalyptic number.

It is an amenable number.

1099989 is a deficient number, since it is larger than the sum of its proper divisors (682155).

1099989 is a wasteful number, since it uses less digits than its factorization.

1099989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 52488, while the sum is 45.

The square root of 1099989 is about 1048.8036041128. The cubic root of 1099989 is about 103.2276674511.

Multiplying 1099989 by its reverse (9899901), we get a square (10889782201089 = 3299967²).

It can be divided in two parts, 109 and 9989, that multiplied together give a palindrome (1088801).

The spelling of 1099989 in words is "one million, ninety-nine thousand, nine hundred eighty-nine".