66566844 has 18 divisors (see below), whose sum is σ = 168266280. Its totient is φ = 22188936.

The previous prime is 66566839. The next prime is 66566867. The reversal of 66566844 is 44866566.

66566844 is a `hidden beast` number, since 6 + 6 + 566 + 84 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×66566844² = 8862289440240672, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66566844.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 924504 + ... + 924575.

Almost surely, 2^66566844 is an apocalyptic number.

It is an amenable number.

66566844 is an abundant number, since it is smaller than the sum of its proper divisors (101699436).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66566844 is a wasteful number, since it uses less digits than its factorization.

66566844 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1849089 (or 1849084 counting only the distinct ones).

The product of its digits is 829440, while the sum is 45.

The square root of 66566844 is about 8158.8506543508. The cubic root of 66566844 is about 405.2776514025.

The spelling of 66566844 in words is "sixty-six million, five hundred sixty-six thousand, eight hundred forty-four".