6646378 has 4 divisors (see below), whose sum is σ = 9969570. Its totient is φ = 3323188.

The previous prime is 6646373. The next prime is 6646399. The reversal of 6646378 is 8736466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 4108729 + 2537649 = 2027^2 + 1593^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 6646378.

It is not an unprimeable number, because it can be changed into a prime (6646373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1661593 + ... + 1661596.

Almost surely, 2^6646378 is an apocalyptic number.

6646378 is a deficient number, since it is larger than the sum of its proper divisors (3323192).

6646378 is a wasteful number, since it uses less digits than its factorization.

6646378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3323191.

The product of its digits is 145152, while the sum is 40.

The square root of 6646378 is about 2578.0570203159. The cubic root of 6646378 is about 188.0160881056.

The spelling of 6646378 in words is "six million, six hundred forty-six thousand, three hundred seventy-eight".