6668987 has 4 divisors (see below), whose sum is σ = 7182000. Its totient is φ = 6155976.

The previous prime is 6668969. The next prime is 6669007. The reversal of 6668987 is 7898666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7898666 = 2 ⋅3949333.

It is a cyclic number.

It is not a de Polignac number, because 6668987 - 2⁸ = 6668731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6668957) 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, 256487 + ... + 256512.

It is an arithmetic number, because the mean of its divisors is an integer number (1795500).

Almost surely, 2^6668987 is an apocalyptic number.

6668987 is a deficient number, since it is larger than the sum of its proper divisors (513013).

6668987 is a wasteful number, since it uses less digits than its factorization.

6668987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513012.

The product of its digits is 870912, while the sum is 50.

The square root of 6668987 is about 2582.4381889989. The cubic root of 6668987 is about 188.2290384161.

The spelling of 6668987 in words is "six million, six hundred sixty-eight thousand, nine hundred eighty-seven".