6447978 has 32 divisors (see below), whose sum is σ = 14488320. Its totient is φ = 2125440.

The previous prime is 6447967. The next prime is 6447983. The reversal of 6447978 is 8797446.

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 15 ways as a sum of consecutive naturals, for example, 4623 + ... + 5853.

It is an arithmetic number, because the mean of its divisors is an integer number (452760).

Almost surely, 2^6447978 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6447978, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7244160).

6447978 is an abundant number, since it is smaller than the sum of its proper divisors (8040342).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6447978 is a wasteful number, since it uses less digits than its factorization.

6447978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1339 (or 1333 counting only the distinct ones).

The product of its digits is 338688, while the sum is 45.

The square root of 6447978 is about 2539.2869077755. The cubic root of 6447978 is about 186.1263449590.

The spelling of 6447978 in words is "six million, four hundred forty-seven thousand, nine hundred seventy-eight".