66685584 has 40 divisors (see below), whose sum is σ = 196882240. Its totient is φ = 19052928.

The previous prime is 66685519. The next prime is 66685609. The reversal of 66685584 is 48558666.

It is a happy number.

66685584 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66685584² = 8893934226842112, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 98899 + ... + 99570.

It is an arithmetic number, because the mean of its divisors is an integer number (4922056).

Almost surely, 2^66685584 is an apocalyptic number.

It is an amenable number.

66685584 is an abundant number, since it is smaller than the sum of its proper divisors (130196656).

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

66685584 is a wasteful number, since it uses less digits than its factorization.

66685584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198487 (or 198481 counting only the distinct ones).

The product of its digits is 1382400, while the sum is 48.

The square root of 66685584 is about 8166.1241724578. The cubic root of 66685584 is about 405.5184824253.

It can be divided in two parts, 666855 and 84, that multiplied together give a triangular number (56015820 = T₁₀₅₈₄).

The spelling of 66685584 in words is "sixty-six million, six hundred eighty-five thousand, five hundred eighty-four".