261256220273 has 2 divisors, whose sum is σ = 261256220274. Its totient is φ = 261256220272.

The previous prime is 261256220221. The next prime is 261256220297. The reversal of 261256220273 is 372022652162.

It is a happy number.

261256220273 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 225342938209 + 35913282064 = 474703^2 + 189508^2 .

It is a cyclic number.

It is not a de Polignac number, because 261256220273 - 2¹⁴ = 261256203889 is a prime.

It is not a weakly prime, because it can be changed into another prime (261253220273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130628110136 + 130628110137.

It is an arithmetic number, because the mean of its divisors is an integer number (130628110137).

Almost surely, 2^261256220273 is an apocalyptic number.

It is an amenable number.

261256220273 is a deficient number, since it is larger than the sum of its proper divisors (1).

261256220273 is an equidigital number, since it uses as much as digits as its factorization.

261256220273 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120960, while the sum is 38.

The spelling of 261256220273 in words is "two hundred sixty-one billion, two hundred fifty-six million, two hundred twenty thousand, two hundred seventy-three".