66539564 has 48 divisors (see below), whose sum is σ = 151760448. Its totient is φ = 24772608.

The previous prime is 66539563. The next prime is 66539611. The reversal of 66539564 is 46593566.

It is not an unprimeable number, because it can be changed into a prime (66539563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 812 + ... + 11564.

It is an arithmetic number, because the mean of its divisors is an integer number (3161676).

Almost surely, 2^66539564 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 66539564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75880224).

66539564 is an abundant number, since it is smaller than the sum of its proper divisors (85220884).

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

66539564 is a wasteful number, since it uses less digits than its factorization.

66539564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10794 (or 10792 counting only the distinct ones).

The product of its digits is 583200, while the sum is 44.

The square root of 66539564 is about 8157.1786789306. The cubic root of 66539564 is about 405.2222810694. Note that the first 4 decimals are identical.

The spelling of 66539564 in words is "sixty-six million, five hundred thirty-nine thousand, five hundred sixty-four".