6666644 has 12 divisors (see below), whose sum is σ = 12280800. Its totient is φ = 3157848.

The previous prime is 6666617. The next prime is 6666679. The reversal of 6666644 is 4466666.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6666598 and 6666607.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43784 + ... + 43935.

It is an arithmetic number, because the mean of its divisors is an integer number (1023400).

Almost surely, 2^6666644 is an apocalyptic number.

It is an amenable number.

6666644 is a deficient number, since it is larger than the sum of its proper divisors (5614156).

6666644 is a wasteful number, since it uses less digits than its factorization.

6666644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87742 (or 87740 counting only the distinct ones).

The product of its digits is 124416, while the sum is 38.

The square root of 6666644 is about 2581.9845080868. The cubic root of 6666644 is about 188.2069924745.

The spelling of 6666644 in words is "six million, six hundred sixty-six thousand, six hundred forty-four".