1686660 has 24 divisors (see below), whose sum is σ = 4722816. Its totient is φ = 449760.

The previous prime is 1686647. The next prime is 1686661. The reversal of 1686660 is 666861.

It is not an unprimeable number, because it can be changed into a prime (1686661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13996 + ... + 14115.

It is an arithmetic number, because the mean of its divisors is an integer number (196784).

2^1686660 is an apocalyptic number.

1686660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1686660 is an abundant number, since it is smaller than the sum of its proper divisors (3036156).

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

1686660 is a wasteful number, since it uses less digits than its factorization.

1686660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28123 (or 28121 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 1686660 is about 1298.7147492810. The cubic root of 1686660 is about 119.0353212948.

It can be divided in two parts, 1686 and 660, that added together give a triangular number (2346 = T₆₈).

The spelling of 1686660 in words is "one million, six hundred eighty-six thousand, six hundred sixty".