261767702756543 has 2 divisors, whose sum is σ = 261767702756544. Its totient is φ = 261767702756542.

The previous prime is 261767702756531. The next prime is 261767702756561. The reversal of 261767702756543 is 345657207767162.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261767702756543 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261767702756503) 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 as a sum of consecutive naturals, namely, 130883851378271 + 130883851378272.

It is an arithmetic number, because the mean of its divisors is an integer number (130883851378272).

Almost surely, 2^{261767702756543} is an apocalyptic number.

261767702756543 is a deficient number, since it is larger than the sum of its proper divisors (1).

261767702756543 is an equidigital number, since it uses as much as digits as its factorization.

261767702756543 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 622339200, while the sum is 68.

The spelling of 261767702756543 in words is "two hundred sixty-one trillion, seven hundred sixty-seven billion, seven hundred two million, seven hundred fifty-six thousand, five hundred forty-three".