66585564 has 60 divisors (see below), whose sum is σ = 175349328. Its totient is φ = 22032000.

The previous prime is 66585559. The next prime is 66585569. The reversal of 66585564 is 46558566.

It is a happy number.

66585564 is a `hidden beast` number, since 6 + 6 + 5 + 85 + 564 = 666.

It is an interprime number because it is at equal distance from previous prime (66585559) and next prime (66585569).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66585569) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 48244 + ... + 49604.

Almost surely, 2^66585564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66585564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87674664).

66585564 is an abundant number, since it is smaller than the sum of its proper divisors (108763764).

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

66585564 is a wasteful number, since it uses less digits than its factorization.

66585564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1528 (or 1517 counting only the distinct ones).

The product of its digits is 864000, while the sum is 45.

The square root of 66585564 is about 8159.9977941173. The cubic root of 66585564 is about 405.3156387152.

The spelling of 66585564 in words is "sixty-six million, five hundred eighty-five thousand, five hundred sixty-four".