66116356813 has 4 divisors (see below), whose sum is σ = 71202230428. Its totient is φ = 61030483200.

The previous prime is 66116356763. The next prime is 66116356847. The reversal of 66116356813 is 31865361166.

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 23883229764 + 42233127049 = 154542^2 + 205507^2 .

It is a cyclic number.

It is not a de Polignac number, because 66116356813 - 2¹⁷ = 66116225741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66116356913) 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, 2542936788 + ... + 2542936813.

It is an arithmetic number, because the mean of its divisors is an integer number (17800557607).

Almost surely, 2^66116356813 is an apocalyptic number.

It is an amenable number.

66116356813 is a deficient number, since it is larger than the sum of its proper divisors (5085873615).

66116356813 is a wasteful number, since it uses less digits than its factorization.

66116356813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5085873614.

The product of its digits is 466560, while the sum is 46.

The spelling of 66116356813 in words is "sixty-six billion, one hundred sixteen million, three hundred fifty-six thousand, eight hundred thirteen".