660571 has 4 divisors (see below), whose sum is σ = 662200. Its totient is φ = 658944.

The previous prime is 660563. The next prime is 660589. The reversal of 660571 is 175066.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 660571 - 2³ = 660563 is a prime.

It is a Duffinian number.

660571 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (660521) 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, 340 + ... + 1198.

It is an arithmetic number, because the mean of its divisors is an integer number (165550).

2⁶⁶⁰⁵⁷¹ is an apocalyptic number.

660571 is a deficient number, since it is larger than the sum of its proper divisors (1629).

660571 is an equidigital number, since it uses as much as digits as its factorization.

660571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 660571 is about 812.7551906940. The cubic root of 660571 is about 87.0909780661.

The spelling of 660571 in words is "six hundred sixty thousand, five hundred seventy-one".