261552510041243 has 2 divisors, whose sum is σ = 261552510041244. Its totient is φ = 261552510041242.

The previous prime is 261552510041209. The next prime is 261552510041293. The reversal of 261552510041243 is 342140015255162.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261552510041243 - 2¹⁰ = 261552510040219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261552510041243.

It is not a weakly prime, because it can be changed into another prime (261552510041293) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130776255020621 + 130776255020622.

It is an arithmetic number, because the mean of its divisors is an integer number (130776255020622).

Almost surely, 2^{261552510041243} is an apocalyptic number.

261552510041243 is a deficient number, since it is larger than the sum of its proper divisors (1).

261552510041243 is an equidigital number, since it uses as much as digits as its factorization.

261552510041243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288000, while the sum is 41.

The spelling of 261552510041243 in words is "two hundred sixty-one trillion, five hundred fifty-two billion, five hundred ten million, forty-one thousand, two hundred forty-three".