666016013060261 has 4 divisors (see below), whose sum is σ = 672126251712300. Its totient is φ = 659905774408224.

The previous prime is 666016013060231. The next prime is 666016013060287. The reversal of 666016013060261 is 162060310610666.

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 249032670231361 + 416983342828900 = 15780769^2 + 20420170^2 .

It is a cyclic number.

It is not a de Polignac number, because 666016013060261 - 2¹⁰ = 666016013059237 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 (666016013060221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3055119325856 + ... + 3055119326073.

It is an arithmetic number, because the mean of its divisors is an integer number (168031562928075).

Almost surely, 2^{666016013060261} is an apocalyptic number.

It is an amenable number.

666016013060261 is a deficient number, since it is larger than the sum of its proper divisors (6110238652039).

666016013060261 is a wasteful number, since it uses less digits than its factorization.

666016013060261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6110238652038.

The product of its (nonzero) digits is 279936, while the sum is 44.

The spelling of 666016013060261 in words is "six hundred sixty-six trillion, sixteen billion, thirteen million, sixty thousand, two hundred sixty-one".