66599899566 has 32 divisors (see below), whose sum is σ = 134387527680. Its totient is φ = 22002374016.

The previous prime is 66599899559. The next prime is 66599899573.

66599899566 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (66599899559) and next prime (66599899573).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66599899491 and 66599899500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 699745 + ... + 789203.

It is an arithmetic number, because the mean of its divisors is an integer number (4199610240).

Almost surely, 2^66599899566 is an apocalyptic number.

66599899566 is an abundant number, since it is smaller than the sum of its proper divisors (67787628114).

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

66599899566 is a wasteful number, since it uses less digits than its factorization.

66599899566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 90568.

The product of its digits is 1700611200, while the sum is 78.

The spelling of 66599899566 in words is "sixty-six billion, five hundred ninety-nine million, eight hundred ninety-nine thousand, five hundred sixty-six".