6649778 has 8 divisors (see below), whose sum is σ = 10206768. Its totient is φ = 3247524.

The previous prime is 6649733. The next prime is 6649801. The reversal of 6649778 is 8779466.

It is a happy number.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38576 + ... + 38747.

It is an arithmetic number, because the mean of its divisors is an integer number (1275846).

Almost surely, 2^6649778 is an apocalyptic number.

6649778 is a deficient number, since it is larger than the sum of its proper divisors (3556990).

6649778 is a wasteful number, since it uses less digits than its factorization.

6649778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77368.

The product of its digits is 508032, while the sum is 47.

The square root of 6649778 is about 2578.7163473325. The cubic root of 6649778 is about 188.0481429444.

The spelling of 6649778 in words is "six million, six hundred forty-nine thousand, seven hundred seventy-eight".