6667707778 has 4 divisors (see below), whose sum is σ = 10001561670. Its totient is φ = 3333853888.

The previous prime is 6667707769. The next prime is 6667707817. The reversal of 6667707778 is 8777077666.

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., 4155994089 + 2511713689 = 64467^2 + 50117^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1666926943 + ... + 1666926946.

Almost surely, 2^6667707778 is an apocalyptic number.

6667707778 is a deficient number, since it is larger than the sum of its proper divisors (3333853892).

6667707778 is a wasteful number, since it uses less digits than its factorization.

6667707778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333853891.

The product of its (nonzero) digits is 29042496, while the sum is 61.

The square root of 6667707778 is about 81656.0333227129. The cubic root of 6667707778 is about 1882.1700249900.

The spelling of 6667707778 in words is "six billion, six hundred sixty-seven million, seven hundred seven thousand, seven hundred seventy-eight".