66509636 has 12 divisors (see below), whose sum is σ = 116597628. Its totient is φ = 33196032.

The previous prime is 66509623. The next prime is 66509669. The reversal of 66509636 is 63690566.

It can be written as a sum of positive squares in 2 ways, for example, as 65286400 + 1223236 = 8080^2 + 1106^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66509593 and 66509602.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12101 + ... + 16716.

It is an arithmetic number, because the mean of its divisors is an integer number (9716469).

Almost surely, 2^66509636 is an apocalyptic number.

It is an amenable number.

66509636 is a deficient number, since it is larger than the sum of its proper divisors (50087992).

66509636 is a wasteful number, since it uses less digits than its factorization.

66509636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29398 (or 29396 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 41.

The square root of 66509636 is about 8155.3440148163. The cubic root of 66509636 is about 405.1615186679.

The spelling of 66509636 in words is "sixty-six million, five hundred nine thousand, six hundred thirty-six".