6404978 has 8 divisors (see below), whose sum is σ = 9661680. Its totient is φ = 3184420.

The previous prime is 6404929. The next prime is 6404987. The reversal of 6404978 is 8794046.

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 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, 8588 + ... + 9303.

It is an arithmetic number, because the mean of its divisors is an integer number (1207710).

Almost surely, 2^6404978 is an apocalyptic number.

6404978 is a deficient number, since it is larger than the sum of its proper divisors (3256702).

6404978 is a wasteful number, since it uses less digits than its factorization.

6404978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18072.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 6404978 is about 2530.8058005307. The cubic root of 6404978 is about 185.7116780135.

The spelling of 6404978 in words is "six million, four hundred four thousand, nine hundred seventy-eight".