1686667 has 2 divisors, whose sum is σ = 1686668. Its totient is φ = 1686666.

The previous prime is 1686661. The next prime is 1686673. The reversal of 1686667 is 7666861.

It is a balanced prime because it is at equal distance from previous prime (1686661) and next prime (1686673).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1686667 is a prime.

It is not a weakly prime, because it can be changed into another prime (1686661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 843333 + 843334.

It is an arithmetic number, because the mean of its divisors is an integer number (843334).

2^1686667 is an apocalyptic number.

1686667 is a deficient number, since it is larger than the sum of its proper divisors (1).

1686667 is an equidigital number, since it uses as much as digits as its factorization.

1686667 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 40.

The square root of 1686667 is about 1298.7174442503. The cubic root of 1686667 is about 119.0354859685.

The spelling of 1686667 in words is "one million, six hundred eighty-six thousand, six hundred sixty-seven".