1688109 has 4 divisors (see below), whose sum is σ = 2250816. Its totient is φ = 1125404.

The previous prime is 1688101. The next prime is 1688123. The reversal of 1688109 is 9018861.

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.

It is a cyclic number.

It is not a de Polignac number, because 1688109 - 2³ = 1688101 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 1688109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281349 + ... + 281354.

It is an arithmetic number, because the mean of its divisors is an integer number (562704).

2^1688109 is an apocalyptic number.

It is an amenable number.

1688109 is a deficient number, since it is larger than the sum of its proper divisors (562707).

1688109 is an equidigital number, since it uses as much as digits as its factorization.

1688109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562706.

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 1688109 is about 1299.2724887413. The cubic root of 1688109 is about 119.0693990601.

The spelling of 1688109 in words is "one million, six hundred eighty-eight thousand, one hundred nine".