1988109 has 6 divisors (see below), whose sum is σ = 2871726. Its totient is φ = 1325400.

The previous prime is 1988101. The next prime is 1988113. The reversal of 1988109 is 9018891.

It can be written as a sum of positive squares in only one way, i.e., 1988100 + 9 = 1410^2 + 3^2 .

It is not a de Polignac number, because 1988109 - 2³ = 1988101 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988101) 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 5 ways as a sum of consecutive naturals, for example, 110442 + ... + 110459.

It is an arithmetic number, because the mean of its divisors is an integer number (478621).

2^1988109 is an apocalyptic number.

It is an amenable number.

1988109 is a deficient number, since it is larger than the sum of its proper divisors (883617).

1988109 is a wasteful number, since it uses less digits than its factorization.

1988109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220907 (or 220904 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 1988109 is about 1410.0031914857. The cubic root of 1988109 is about 125.7419131405.

The spelling of 1988109 in words is "one million, nine hundred eighty-eight thousand, one hundred nine".