666366284553685 has 4 divisors (see below), whose sum is σ = 799639541464428. Its totient is φ = 533093027642944.

The previous prime is 666366284553589. The next prime is 666366284553689. The reversal of 666366284553685 is 586355482663666.

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 441828586838961 + 224537697714724 = 21019719^2 + 14984582^2 .

It is a cyclic number.

It is not a de Polignac number, because 666366284553685 - 2²⁹ = 666365747682773 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 (666366284553689) 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, 66636628455364 + ... + 66636628455373.

It is an arithmetic number, because the mean of its divisors is an integer number (199909885366107).

Almost surely, 2^{666366284553685} is an apocalyptic number.

It is an amenable number.

666366284553685 is a deficient number, since it is larger than the sum of its proper divisors (133273256910743).

666366284553685 is a wasteful number, since it uses less digits than its factorization.

666366284553685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133273256910742.

The product of its digits is 26873856000, while the sum is 79.

The spelling of 666366284553685 in words is "six hundred sixty-six trillion, three hundred sixty-six billion, two hundred eighty-four million, five hundred fifty-three thousand, six hundred eighty-five".