6688667 has 4 divisors (see below), whose sum is σ = 7082136. Its totient is φ = 6295200.

The previous prime is 6688663. The next prime is 6688673. The reversal of 6688667 is 7668866.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7668866 = 2 ⋅3834433.

It is a cyclic number.

It is not a de Polignac number, because 6688667 - 2² = 6688663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6688663) 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, 196709 + ... + 196742.

It is an arithmetic number, because the mean of its divisors is an integer number (1770534).

Almost surely, 2^6688667 is an apocalyptic number.

6688667 is a deficient number, since it is larger than the sum of its proper divisors (393469).

6688667 is a wasteful number, since it uses less digits than its factorization.

6688667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393468.

The product of its digits is 580608, while the sum is 47.

The square root of 6688667 is about 2586.2457346509. The cubic root of 6688667 is about 188.4140095183.

The spelling of 6688667 in words is "six million, six hundred eighty-eight thousand, six hundred sixty-seven".