66641154617 has 4 divisors (see below), whose sum is σ = 67554047220. Its totient is φ = 65728262016.

The previous prime is 66641154607. The next prime is 66641154631. The reversal of 66641154617 is 71645114666.

66641154617 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: 71645114666 = 2 ⋅35822557333.

It can be written as a sum of positive squares in 2 ways, for example, as 20603444521 + 46037710096 = 143539^2 + 214564^2 .

It is a cyclic number.

It is not a de Polignac number, because 66641154617 - 2²⁰ = 66640106041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66641154607) 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, 456446192 + ... + 456446337.

It is an arithmetic number, because the mean of its divisors is an integer number (16888511805).

Almost surely, 2^66641154617 is an apocalyptic number.

It is an amenable number.

66641154617 is a deficient number, since it is larger than the sum of its proper divisors (912892603).

66641154617 is an equidigital number, since it uses as much as digits as its factorization.

66641154617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912892602.

The product of its digits is 725760, while the sum is 47.

The spelling of 66641154617 in words is "sixty-six billion, six hundred forty-one million, one hundred fifty-four thousand, six hundred seventeen".