6645791 has 4 divisors (see below), whose sum is σ = 6650952. Its totient is φ = 6640632.

The previous prime is 6645787. The next prime is 6645799. The reversal of 6645791 is 1975466.

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 6645791 - 2² = 6645787 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 (6645799) 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, 1136 + ... + 3818.

It is an arithmetic number, because the mean of its divisors is an integer number (1662738).

Almost surely, 2^6645791 is an apocalyptic number.

6645791 is a deficient number, since it is larger than the sum of its proper divisors (5161).

6645791 is a wasteful number, since it uses less digits than its factorization.

6645791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5160.

The product of its digits is 45360, while the sum is 38.

The square root of 6645791 is about 2577.9431723760. The cubic root of 6645791 is about 188.0105528255.

The spelling of 6645791 in words is "six million, six hundred forty-five thousand, seven hundred ninety-one".