6660571 has 4 divisors (see below), whose sum is σ = 6815512. Its totient is φ = 6505632.

The previous prime is 6660557. The next prime is 6660587. The reversal of 6660571 is 1750666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1750666 = 2 ⋅875333.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6660571 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6660551) 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 in 3 ways as a sum of consecutive naturals, for example, 77406 + ... + 77491.

It is an arithmetic number, because the mean of its divisors is an integer number (1703878).

Almost surely, 2^6660571 is an apocalyptic number.

6660571 is the 1380-th centered heptagonal number.

6660571 is a deficient number, since it is larger than the sum of its proper divisors (154941).

6660571 is a wasteful number, since it uses less digits than its factorization.

6660571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154940.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 6660571 is about 2580.8082067445. The cubic root of 6660571 is about 188.1498258647.

The spelling of 6660571 in words is "six million, six hundred sixty thousand, five hundred seventy-one".