561165665011 has 4 divisors (see below), whose sum is σ = 641332188592. Its totient is φ = 480999141432.

The previous prime is 561165665003. The next prime is 561165665131. The reversal of 561165665011 is 110566561165.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 110566561165 = 5 ⋅22113312233.

It is a cyclic number.

It is not a de Polignac number, because 561165665011 - 2³ = 561165665003 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (561165065011) 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, 40083261780 + ... + 40083261793.

It is an arithmetic number, because the mean of its divisors is an integer number (160333047148).

Almost surely, 2^561165665011 is an apocalyptic number.

561165665011 is a deficient number, since it is larger than the sum of its proper divisors (80166523581).

561165665011 is an equidigital number, since it uses as much as digits as its factorization.

561165665011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80166523580.

The product of its (nonzero) digits is 162000, while the sum is 43.

The spelling of 561165665011 in words is "five hundred sixty-one billion, one hundred sixty-five million, six hundred sixty-five thousand, eleven".