665566110641 has 4 divisors (see below), whose sum is σ = 670424257572. Its totient is φ = 660707963712.

The previous prime is 665566110617. The next prime is 665566110661. The reversal of 665566110641 is 146011665566.

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 504520407616 + 161045703025 = 710296^2 + 401305^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-665566110641 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (665566110661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2429073260 + ... + 2429073533.

It is an arithmetic number, because the mean of its divisors is an integer number (167606064393).

Almost surely, 2^665566110641 is an apocalyptic number.

It is an amenable number.

665566110641 is a deficient number, since it is larger than the sum of its proper divisors (4858146931).

665566110641 is a wasteful number, since it uses less digits than its factorization.

665566110641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4858146930.

The product of its (nonzero) digits is 777600, while the sum is 47.

The spelling of 665566110641 in words is "six hundred sixty-five billion, five hundred sixty-six million, one hundred ten thousand, six hundred forty-one".