6655666 has 4 divisors (see below), whose sum is σ = 9983502. Its totient is φ = 3327832.

The previous prime is 6655661. The next prime is 6655667. The reversal of 6655666 is 6665566.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 6426225 + 229441 = 2535^2 + 479^2 .

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (6655661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1663915 + ... + 1663918.

Almost surely, 2^6655666 is an apocalyptic number.

6655666 is a deficient number, since it is larger than the sum of its proper divisors (3327836).

6655666 is a wasteful number, since it uses less digits than its factorization.

6655666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3327835.

The product of its digits is 194400, while the sum is 40.

The square root of 6655666 is about 2579.8577480164. The cubic root of 6655666 is about 188.1036285476.

The spelling of 6655666 in words is "six million, six hundred fifty-five thousand, six hundred sixty-six".