66603606899 has 4 divisors (see below), whose sum is σ = 66611573640. Its totient is φ = 66595640160.

The previous prime is 66603606863. The next prime is 66603606911. The reversal of 66603606899 is 99860630666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99860630666 = 2 ⋅49930315333.

It is a cyclic number.

It is not a de Polignac number, because 66603606899 - 2²⁸ = 66335171443 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66603606809) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3970817 + ... + 3987554.

It is an arithmetic number, because the mean of its divisors is an integer number (16652893410).

Almost surely, 2^66603606899 is an apocalyptic number.

66603606899 is a deficient number, since it is larger than the sum of its proper divisors (7966741).

66603606899 is an equidigital number, since it uses as much as digits as its factorization.

66603606899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7966740.

The product of its (nonzero) digits is 15116544, while the sum is 59.

The spelling of 66603606899 in words is "sixty-six billion, six hundred three million, six hundred six thousand, eight hundred ninety-nine".