6645671 has 4 divisors (see below), whose sum is σ = 6739344. Its totient is φ = 6552000.

The previous prime is 6645641. The next prime is 6645677. The reversal of 6645671 is 1765466.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1765466 = 2 ⋅882733.

It is a cyclic number.

It is not a de Polignac number, because 6645671 - 2¹⁰ = 6644647 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 (6645677) 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, 46730 + ... + 46871.

It is an arithmetic number, because the mean of its divisors is an integer number (1684836).

Almost surely, 2^6645671 is an apocalyptic number.

6645671 is a deficient number, since it is larger than the sum of its proper divisors (93673).

6645671 is an equidigital number, since it uses as much as digits as its factorization.

6645671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93672.

The product of its digits is 30240, while the sum is 35.

The square root of 6645671 is about 2577.9198979022. The cubic root of 6645671 is about 188.0094212119.

The spelling of 6645671 in words is "six million, six hundred forty-five thousand, six hundred seventy-one".