66512564 has 12 divisors (see below), whose sum is σ = 116541600. Its totient is φ = 33214968.

The previous prime is 66512561. The next prime is 66512599. The reversal of 66512564 is 46521566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66512561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6554 + ... + 13265.

It is an arithmetic number, because the mean of its divisors is an integer number (9711800).

Almost surely, 2^66512564 is an apocalyptic number.

It is an amenable number.

66512564 is a deficient number, since it is larger than the sum of its proper divisors (50029036).

66512564 is a wasteful number, since it uses less digits than its factorization.

66512564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20662 (or 20660 counting only the distinct ones).

The product of its digits is 43200, while the sum is 35.

The square root of 66512564 is about 8155.5235270337. The cubic root of 66512564 is about 405.1674641499.

It can be divided in two parts, 66512 and 564, that added together give a palindrome (67076).

The spelling of 66512564 in words is "sixty-six million, five hundred twelve thousand, five hundred sixty-four".