1688740 has 12 divisors (see below), whose sum is σ = 3546396. Its totient is φ = 675488.

The previous prime is 1688681. The next prime is 1688741. The reversal of 1688740 is 478861.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 952576 + 736164 = 976^2 + 858^2 .

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 1688696 and 1688705.

It is not an unprimeable number, because it can be changed into a prime (1688741) 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, 42199 + ... + 42238.

It is an arithmetic number, because the mean of its divisors is an integer number (295533).

2^1688740 is an apocalyptic number.

1688740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1688740 is an abundant number, since it is smaller than the sum of its proper divisors (1857656).

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

1688740 is a wasteful number, since it uses less digits than its factorization.

1688740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84446 (or 84444 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 1688740 is about 1299.5152942540. The cubic root of 1688740 is about 119.0842329031.

The spelling of 1688740 in words is "one million, six hundred eighty-eight thousand, seven hundred forty".