6644712778 has 8 divisors (see below), whose sum is σ = 10873166400. Its totient is φ = 3020323980.

The previous prime is 6644712743. The next prime is 6644712779. The reversal of 6644712778 is 8772174466.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (6644712779) 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, 151016178 + ... + 151016221.

It is an arithmetic number, because the mean of its divisors is an integer number (1359145800).

Almost surely, 2^6644712778 is an apocalyptic number.

6644712778 is a deficient number, since it is larger than the sum of its proper divisors (4228453622).

6644712778 is a wasteful number, since it uses less digits than its factorization.

6644712778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302032412.

The product of its digits is 3161088, while the sum is 52.

The square root of 6644712778 is about 81515.1076672294. The cubic root of 6644712778 is about 1880.0038458123.

The spelling of 6644712778 in words is "six billion, six hundred forty-four million, seven hundred twelve thousand, seven hundred seventy-eight".