6646861 has 4 divisors (see below), whose sum is σ = 7158172. Its totient is φ = 6135552.

The previous prime is 6646859. The next prime is 6646867. The reversal of 6646861 is 1686466.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3924361 + 2722500 = 1981^2 + 1650^2 .

It is a cyclic number.

It is not a de Polignac number, because 6646861 - 2¹ = 6646859 is a prime.

It is a super-2 number, since 2×6646861² = 88361522306642, which contains 22 as substring.

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 6646861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6646867) 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, 255636 + ... + 255661.

It is an arithmetic number, because the mean of its divisors is an integer number (1789543).

Almost surely, 2^6646861 is an apocalyptic number.

It is an amenable number.

6646861 is a deficient number, since it is larger than the sum of its proper divisors (511311).

6646861 is a wasteful number, since it uses less digits than its factorization.

6646861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511310.

The product of its digits is 41472, while the sum is 37.

The square root of 6646861 is about 2578.1506938114. The cubic root of 6646861 is about 188.0206424444.

The spelling of 6646861 in words is "six million, six hundred forty-six thousand, eight hundred sixty-one".