66646844 has 12 divisors (see below), whose sum is σ = 127234968. Its totient is φ = 30294000.

The previous prime is 66646829. The next prime is 66646897. The reversal of 66646844 is 44864666.

It is a Harshad number since it is a multiple of its sum of digits (44), and also a Moran number because the ratio is a prime number: 1514701 = 66646844 / (6 + 6 + 6 + 4 + 6 + 8 + 4 + 4).

It is a zygodrome in base 2.

It is a junction number, because it is equal to n+sod(n) for n = 66646795 and 66646804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 757307 + ... + 757394.

It is an arithmetic number, because the mean of its divisors is an integer number (10602914).

Almost surely, 2^66646844 is an apocalyptic number.

It is an amenable number.

66646844 is a deficient number, since it is larger than the sum of its proper divisors (60588124).

66646844 is a wasteful number, since it uses less digits than its factorization.

66646844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1514716 (or 1514714 counting only the distinct ones).

The product of its digits is 663552, while the sum is 44.

The square root of 66646844 is about 8163.7518335628. The cubic root of 66646844 is about 405.4399405668.

The spelling of 66646844 in words is "sixty-six million, six hundred forty-six thousand, eight hundred forty-four".