6644878 has 4 divisors (see below), whose sum is σ = 9967320. Its totient is φ = 3322438.

The previous prime is 6644873. The next prime is 6644879. The reversal of 6644878 is 8784466.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6644873) by changing a digit.

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 as a sum of consecutive naturals, namely, 1661218 + ... + 1661221.

It is an arithmetic number, because the mean of its divisors is an integer number (2491830).

Almost surely, 2^6644878 is an apocalyptic number.

6644878 is a deficient number, since it is larger than the sum of its proper divisors (3322442).

6644878 is a wasteful number, since it uses less digits than its factorization.

6644878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3322441.

The product of its digits is 258048, while the sum is 43.

The square root of 6644878 is about 2577.7660871382. The cubic root of 6644878 is about 188.0019427896.

Subtracting from 6644878 its sum of digits (43), we obtain a triangular number (6644835 = T₃₆₄₅).

It can be divided in two parts, 66 and 44878, that added together give a palindrome (44944).

The spelling of 6644878 in words is "six million, six hundred forty-four thousand, eight hundred seventy-eight".