1688688 has 50 divisors (see below), whose sum is σ = 4891304. Its totient is φ = 562464.

The previous prime is 1688681. The next prime is 1688741. The reversal of 1688688 is 8868861.

It is a happy number.

It is a super-2 number, since 2×1688688² = 5703334322688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688681) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 645 + ... + 1947.

2^1688688 is an apocalyptic number.

1688688 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1688688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2445652).

1688688 is an abundant number, since it is smaller than the sum of its proper divisors (3202616).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1688688 is a wasteful number, since it uses less digits than its factorization.

1688688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1323 (or 1308 counting only the distinct ones).

The product of its digits is 147456, while the sum is 45.

The square root of 1688688 is about 1299.4952866402. The cubic root of 1688688 is about 119.0830106025.

The spelling of 1688688 in words is "one million, six hundred eighty-eight thousand, six hundred eighty-eight".