6661871 has 4 divisors (see below), whose sum is σ = 6771144. Its totient is φ = 6552600.

The previous prime is 6661849. The next prime is 6661873. The reversal of 6661871 is 1781666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1781666 = 2 ⋅890833.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6661871 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 (6661873) 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, 54545 + ... + 54666.

It is an arithmetic number, because the mean of its divisors is an integer number (1692786).

Almost surely, 2^6661871 is an apocalyptic number.

6661871 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

6661871 is a deficient number, since it is larger than the sum of its proper divisors (109273).

6661871 is a wasteful number, since it uses less digits than its factorization.

6661871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109272.

The product of its digits is 12096, while the sum is 35.

The square root of 6661871 is about 2581.0600535439. The cubic root of 6661871 is about 188.1620659996.

The spelling of 6661871 in words is "six million, six hundred sixty-one thousand, eight hundred seventy-one".