6628891 has 4 divisors (see below), whose sum is σ = 6977800. Its totient is φ = 6279984.

The previous prime is 6628879. The next prime is 6628943. The reversal of 6628891 is 1988266.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6628891 - 2⁵ = 6628859 is a prime.

It is a Duffinian number.

6628891 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (6623891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174426 + ... + 174463.

It is an arithmetic number, because the mean of its divisors is an integer number (1744450).

Almost surely, 2^6628891 is an apocalyptic number.

6628891 is a deficient number, since it is larger than the sum of its proper divisors (348909).

6628891 is a wasteful number, since it uses less digits than its factorization.

6628891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 348908.

The product of its digits is 41472, while the sum is 40.

The square root of 6628891 is about 2574.6632789551. The cubic root of 6628891 is about 187.8510495914.

The spelling of 6628891 in words is "six million, six hundred twenty-eight thousand, eight hundred ninety-one".