1686740 has 72 divisors (see below), whose sum is σ = 4223016. Its totient is φ = 563200.

The previous prime is 1686703. The next prime is 1686743. The reversal of 1686740 is 476861.

It can be written as a sum of positive squares in 4 ways, for example, as 58564 + 1628176 = 242^2 + 1276^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1686697 and 1686706.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1686743) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41120 + ... + 41160.

It is an arithmetic number, because the mean of its divisors is an integer number (58653).

2^1686740 is an apocalyptic number.

1686740 is a gapful number since it is divisible by the number (10) 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 1686740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2111508).

1686740 is an abundant number, since it is smaller than the sum of its proper divisors (2536276).

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

1686740 is a wasteful number, since it uses less digits than its factorization.

1686740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 76 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 1686740 is about 1298.7455485968. The cubic root of 1686740 is about 119.0372032538.

The spelling of 1686740 in words is "one million, six hundred eighty-six thousand, seven hundred forty".