261144045222163 has 4 divisors (see below), whose sum is σ = 264449666047840. Its totient is φ = 257838424396488.

The previous prime is 261144045222157. The next prime is 261144045222197. The reversal of 261144045222163 is 361222540441162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261144045222163 - 2³⁷ = 261006606268691 is a prime.

It is a super-2 number, since 2×261144045222163² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261144045222103) 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, 1652810412720 + ... + 1652810412877.

It is an arithmetic number, because the mean of its divisors is an integer number (66112416511960).

Almost surely, 2^{261144045222163} is an apocalyptic number.

261144045222163 is a deficient number, since it is larger than the sum of its proper divisors (3305620825677).

261144045222163 is an equidigital number, since it uses as much as digits as its factorization.

261144045222163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3305620825676.

The product of its (nonzero) digits is 552960, while the sum is 43.

The spelling of 261144045222163 in words is "two hundred sixty-one trillion, one hundred forty-four billion, forty-five million, two hundred twenty-two thousand, one hundred sixty-three".