66194689249 has 4 divisors (see below), whose sum is σ = 71286588436. Its totient is φ = 61102790064.

The previous prime is 66194689229. The next prime is 66194689273. The reversal of 66194689249 is 94298649166.

66194689249 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, and also an emirpimes, since its reverse is a distinct semiprime: 94298649166 = 2 ⋅47149324583.

It can be written as a sum of positive squares in 2 ways, for example, as 3441934224 + 62752755025 = 58668^2 + 250505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66194689249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66194689229) 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, 2545949574 + ... + 2545949599.

It is an arithmetic number, because the mean of its divisors is an integer number (17821647109).

Almost surely, 2^66194689249 is an apocalyptic number.

It is an amenable number.

66194689249 is a deficient number, since it is larger than the sum of its proper divisors (5091899187).

66194689249 is a wasteful number, since it uses less digits than its factorization.

66194689249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5091899186.

The product of its digits is 40310784, while the sum is 64.

The spelling of 66194689249 in words is "sixty-six billion, one hundred ninety-four million, six hundred eighty-nine thousand, two hundred forty-nine".