66599999 has 8 divisors (see below), whose sum is σ = 70590528. Its totient is φ = 62617600.

The previous prime is 66599989. The next prime is 66600029. The reversal of 66599999 is 99999566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66599999 is a prime.

66599999 is a modest number, since divided by 9999 gives 6659 as remainder.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66599969) 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, 25994 + ... + 28440.

It is an arithmetic number, because the mean of its divisors is an integer number (8823816).

Almost surely, 2^66599999 is an apocalyptic number.

66599999 is a deficient number, since it is larger than the sum of its proper divisors (3990529).

66599999 is a wasteful number, since it uses less digits than its factorization.

66599999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4065.

The product of its digits is 10628820, while the sum is 62.

The square root of 66599999 is about 8160.8822439734. The cubic root of 66599999 is about 405.3449258867.

The spelling of 66599999 in words is "sixty-six million, five hundred ninety-nine thousand, nine hundred ninety-nine".