66509708 has 24 divisors (see below), whose sum is σ = 119709744. Its totient is φ = 32313600.

The previous prime is 66509701. The next prime is 66509713. The reversal of 66509708 is 80790566.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is not an unprimeable number, because it can be changed into a prime (66509701) 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 7 ways as a sum of consecutive naturals, for example, 49688 + ... + 51008.

It is an arithmetic number, because the mean of its divisors is an integer number (4987906).

Almost surely, 2^66509708 is an apocalyptic number.

It is an amenable number.

66509708 is a deficient number, since it is larger than the sum of its proper divisors (53200036).

66509708 is a wasteful number, since it uses less digits than its factorization.

66509708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1673 (or 1671 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 66509708 is about 8155.3484290985. The cubic root of 66509708 is about 405.1616648704.

The spelling of 66509708 in words is "sixty-six million, five hundred nine thousand, seven hundred eight".