6666999 has 4 divisors (see below), whose sum is σ = 8889336. Its totient is φ = 4444664.

The previous prime is 6666991. The next prime is 6667019. The reversal of 6666999 is 9996666.

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 6666999 - 2³ = 6666991 is a prime.

It is a D-number.

It is a plaindrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6666991) 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, 1111164 + ... + 1111169.

It is an arithmetic number, because the mean of its divisors is an integer number (2222334).

Almost surely, 2^6666999 is an apocalyptic number.

6666999 is a deficient number, since it is larger than the sum of its proper divisors (2222337).

6666999 is a wasteful number, since it uses less digits than its factorization.

6666999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2222336.

The product of its digits is 944784, while the sum is 51.

The square root of 6666999 is about 2582.0532527429. The cubic root of 6666999 is about 188.2103331006.

The spelling of 6666999 in words is "six million, six hundred sixty-six thousand, nine hundred ninety-nine".