1686138 has 8 divisors (see below), whose sum is σ = 3372288. Its totient is φ = 562044.

The previous prime is 1686137. The next prime is 1686143. The reversal of 1686138 is 8316861.

It is a sphenic number, since it is the product of 3 distinct primes.

1686138 is an admirable number.

It is a super-2 number, since 2×1686138² = 5686122710088, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1686099 and 1686108.

It is not an unprimeable number, because it can be changed into a prime (1686133) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 140506 + ... + 140517.

It is an arithmetic number, because the mean of its divisors is an integer number (421536).

2^1686138 is an apocalyptic number.

1686138 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1686138 is a wasteful number, since it uses less digits than its factorization.

1686138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 281028.

The product of its digits is 6912, while the sum is 33.

The square root of 1686138 is about 1298.5137658107. The cubic root of 1686138 is about 119.0230400508.

The spelling of 1686138 in words is "one million, six hundred eighty-six thousand, one hundred thirty-eight".