1686366 has 64 divisors (see below), whose sum is σ = 4354560. Its totient is φ = 478080.

The previous prime is 1686353. The next prime is 1686367. The reversal of 1686366 is 6636861.

1686366 is a `hidden beast` number, since 16 + 8 + 636 + 6 = 666.

1686366 is a nontrivial binomial coefficient, being equal to C(1837, 2).

It is a self number, because there is not a number n which added to its sum of digits gives 1686366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1686367) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10015 + ... + 10181.

It is an arithmetic number, because the mean of its divisors is an integer number (68040).

2^1686366 is an apocalyptic number.

1686366 is the 1836-th triangular number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1686366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2177280).

1686366 is an abundant number, since it is smaller than the sum of its proper divisors (2668194).

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

1686366 is a wasteful number, since it uses less digits than its factorization.

1686366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 206 (or 200 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 1686366 is about 1298.6015555204. The cubic root of 1686366 is about 119.0284045840.

The spelling of 1686366 in words is "one million, six hundred eighty-six thousand, three hundred sixty-six".