66166117603 has 4 divisors (see below), whose sum is σ = 67704864568. Its totient is φ = 64627370640.

The previous prime is 66166117601. The next prime is 66166117609. The reversal of 66166117603 is 30671166166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66166117603 - 2¹ = 66166117601 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 1538746921 = 66166117603 / (6 + 6 + 1 + 6 + 6 + 1 + 1 + 7 + 6 + 0 + 3).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66166117603.

It is not an unprimeable number, because it can be changed into a prime (66166117601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 769373418 + ... + 769373503.

It is an arithmetic number, because the mean of its divisors is an integer number (16926216142).

Almost surely, 2^66166117603 is an apocalyptic number.

66166117603 is a deficient number, since it is larger than the sum of its proper divisors (1538746965).

66166117603 is a wasteful number, since it uses less digits than its factorization.

66166117603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538746964.

The product of its (nonzero) digits is 163296, while the sum is 43.

The spelling of 66166117603 in words is "sixty-six billion, one hundred sixty-six million, one hundred seventeen thousand, six hundred three".