6664987 has 4 divisors (see below), whose sum is σ = 7617136. Its totient is φ = 5712840.

The previous prime is 6664979. The next prime is 6664997. The reversal of 6664987 is 7894666.

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

It is not a de Polignac number, because 6664987 - 2³ = 6664979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6664937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 476064 + ... + 476077.

It is an arithmetic number, because the mean of its divisors is an integer number (1904284).

Almost surely, 2^6664987 is an apocalyptic number.

6664987 is a deficient number, since it is larger than the sum of its proper divisors (952149).

6664987 is an equidigital number, since it uses as much as digits as its factorization.

6664987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 952148.

The product of its digits is 435456, while the sum is 46.

The square root of 6664987 is about 2581.6636109300. The cubic root of 6664987 is about 188.1913981801.

The spelling of 6664987 in words is "six million, six hundred sixty-four thousand, nine hundred eighty-seven".