6660813 has 4 divisors (see below), whose sum is σ = 8881088. Its totient is φ = 4440540.

The previous prime is 6660809. The next prime is 6660859. The reversal of 6660813 is 3180666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 6660813 - 2² = 6660809 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6660113) 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, 1110133 + ... + 1110138.

It is an arithmetic number, because the mean of its divisors is an integer number (2220272).

Almost surely, 2^6660813 is an apocalyptic number.

It is an amenable number.

6660813 is a deficient number, since it is larger than the sum of its proper divisors (2220275).

6660813 is a wasteful number, since it uses less digits than its factorization.

6660813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2220274.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 6660813 is about 2580.8550908565. The cubic root of 6660813 is about 188.1521045335.

The spelling of 6660813 in words is "six million, six hundred sixty thousand, eight hundred thirteen".