66853388785 has 4 divisors (see below), whose sum is σ = 80224066548. Its totient is φ = 53482711024.

The previous prime is 66853388783. The next prime is 66853388837. The reversal of 66853388785 is 58788335866.

66853388785 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18430506081 + 48422882704 = 135759^2 + 220052^2 .

It is a cyclic number.

It is not a de Polignac number, because 66853388785 - 2¹ = 66853388783 is a prime.

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 66853388785.

It is not an unprimeable number, because it can be changed into a prime (66853388783) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6685338874 + ... + 6685338883.

It is an arithmetic number, because the mean of its divisors is an integer number (20056016637).

Almost surely, 2^66853388785 is an apocalyptic number.

It is an amenable number.

66853388785 is a deficient number, since it is larger than the sum of its proper divisors (13370677763).

66853388785 is a wasteful number, since it uses less digits than its factorization.

66853388785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13370677762.

The product of its digits is 232243200, while the sum is 67.

The spelling of 66853388785 in words is "sixty-six billion, eight hundred fifty-three million, three hundred eighty-eight thousand, seven hundred eighty-five".