660871 has 4 divisors (see below), whose sum is σ = 662544. Its totient is φ = 659200.

The previous prime is 660853. The next prime is 660887. The reversal of 660871 is 178066.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660871 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126 + ... + 1156.

It is an arithmetic number, because the mean of its divisors is an integer number (165636).

2⁶⁶⁰⁸⁷¹ is an apocalyptic number.

660871 is a deficient number, since it is larger than the sum of its proper divisors (1673).

660871 is a wasteful number, since it uses less digits than its factorization.

660871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 660871 is about 812.9397271631. The cubic root of 660871 is about 87.1041602672.

The spelling of 660871 in words is "six hundred sixty thousand, eight hundred seventy-one".