1686641 has 8 divisors (see below), whose sum is σ = 1858464. Its totient is φ = 1517920.

The previous prime is 1686637. The next prime is 1686647. The reversal of 1686641 is 1466861.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1686641 - 2² = 1686637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 1686598 and 1686607.

It is not an unprimeable number, because it can be changed into a prime (1686647) 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, 461 + ... + 1893.

It is an arithmetic number, because the mean of its divisors is an integer number (232308).

2^1686641 is an apocalyptic number.

1686641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1686641 is a deficient number, since it is larger than the sum of its proper divisors (171823).

1686641 is a wasteful number, since it uses less digits than its factorization.

1686641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1551.

The product of its digits is 6912, while the sum is 32.

The square root of 1686641 is about 1298.7074343362. The cubic root of 1686641 is about 119.0348743207.

The spelling of 1686641 in words is "one million, six hundred eighty-six thousand, six hundred forty-one".