1660871 has 2 divisors, whose sum is σ = 1660872. Its totient is φ = 1660870.

The previous prime is 1660843. The next prime is 1660873. The reversal of 1660871 is 1780661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1660871 is a prime.

Together with 1660873, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1660873) 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 as a sum of consecutive naturals, namely, 830435 + 830436.

It is an arithmetic number, because the mean of its divisors is an integer number (830436).

2^1660871 is an apocalyptic number.

1660871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1660871 is an equidigital number, since it uses as much as digits as its factorization.

1660871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 29.

The square root of 1660871 is about 1288.7478418993. The cubic root of 1660871 is about 118.4255200879.

The spelling of 1660871 in words is "one million, six hundred sixty thousand, eight hundred seventy-one".