6406778 has 16 divisors (see below), whose sum is σ = 11019264. Its totient is φ = 2736720.

The previous prime is 6406759. The next prime is 6406787. The reversal of 6406778 is 8776046.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5351 + ... + 6437.

It is an arithmetic number, because the mean of its divisors is an integer number (688704).

Almost surely, 2^6406778 is an apocalyptic number.

6406778 is a deficient number, since it is larger than the sum of its proper divisors (4612486).

6406778 is a wasteful number, since it uses less digits than its factorization.

6406778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1517.

The product of its (nonzero) digits is 56448, while the sum is 38.

The square root of 6406778 is about 2531.1613935109. The cubic root of 6406778 is about 185.7290733224.

The spelling of 6406778 in words is "six million, four hundred six thousand, seven hundred seventy-eight".