1098999 has 24 divisors (see below), whose sum is σ = 1836432. Its totient is φ = 625920.

The previous prime is 1098989. The next prime is 1099031. The reversal of 1098999 is 9998901.

It is not a de Polignac number, because 1098999 - 2⁵ = 1098967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1098989) 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 23 ways as a sum of consecutive naturals, for example, 1357 + ... + 2009.

It is an arithmetic number, because the mean of its divisors is an integer number (76518).

2^1098999 is an apocalyptic number.

1098999 is a deficient number, since it is larger than the sum of its proper divisors (737433).

1098999 is a wasteful number, since it uses less digits than its factorization.

1098999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 687 (or 684 counting only the distinct ones).

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

The square root of 1098999 is about 1048.3315315300. The cubic root of 1098999 is about 103.1966895459.

The spelling of 1098999 in words is "one million, ninety-eight thousand, nine hundred ninety-nine".