66659584 has 72 divisors (see below), whose sum is σ = 144040680. Its totient is φ = 30777344.

The previous prime is 66659569. The next prime is 66659587. The reversal of 66659584 is 48595666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 18662400 + 47997184 = 4320^2 + 6928^2 .

Its product of digits (1555200) is a multiple of the sum of its prime divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66659587) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1257702 + ... + 1257754.

It is an arithmetic number, because the mean of its divisors is an integer number (2000565).

Almost surely, 2^66659584 is an apocalyptic number.

66659584 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66659584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72020340).

66659584 is an abundant number, since it is smaller than the sum of its proper divisors (77381096).

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

66659584 is an frugal number, since it uses more digits than its factorization.

66659584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 72 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 49.

The square root of 66659584 is about 8164.5320747732. The cubic root of 66659584 is about 405.4657731266.

The spelling of 66659584 in words is "sixty-six million, six hundred fifty-nine thousand, five hundred eighty-four".