6378661 has 4 divisors (see below), whose sum is σ = 6714400. Its totient is φ = 6042924.

The previous prime is 6378629. The next prime is 6378703. The reversal of 6378661 is 1668736.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6378661 - 2⁵ = 6378629 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6378661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6378611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 167841 + ... + 167878.

It is an arithmetic number, because the mean of its divisors is an integer number (1678600).

Almost surely, 2^6378661 is an apocalyptic number.

It is an amenable number.

6378661 is a deficient number, since it is larger than the sum of its proper divisors (335739).

6378661 is a wasteful number, since it uses less digits than its factorization.

6378661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 335738.

The product of its digits is 36288, while the sum is 37.

The square root of 6378661 is about 2525.6011165661. The cubic root of 6378661 is about 185.4569759491.

The spelling of 6378661 in words is "six million, three hundred seventy-eight thousand, six hundred sixty-one".