6678621 has 6 divisors (see below), whose sum is σ = 9646910. Its totient is φ = 4452408.

The previous prime is 6678593. The next prime is 6678629. The reversal of 6678621 is 1268766.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 3956121 + 2722500 = 1989^2 + 1650^2 .

It is not a de Polignac number, because 6678621 - 2⁹ = 6678109 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6678629) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 371026 + ... + 371043.

Almost surely, 2^6678621 is an apocalyptic number.

It is an amenable number.

6678621 is a deficient number, since it is larger than the sum of its proper divisors (2968289).

6678621 is a wasteful number, since it uses less digits than its factorization.

6678621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 742075 (or 742072 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 6678621 is about 2584.3028073351. The cubic root of 6678621 is about 188.3196331869.

It can be divided in two parts, 66 and 78621, that added together give a palindrome (78687).

The spelling of 6678621 in words is "six million, six hundred seventy-eight thousand, six hundred twenty-one".