261155161344643 has 2 divisors, whose sum is σ = 261155161344644. Its totient is φ = 261155161344642.

The previous prime is 261155161344593. The next prime is 261155161344659. The reversal of 261155161344643 is 346443161551162.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261155161344643 is a prime.

It is not a weakly prime, because it can be changed into another prime (261155171344643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130577580672321 + 130577580672322.

It is an arithmetic number, because the mean of its divisors is an integer number (130577580672322).

Almost surely, 2^{261155161344643} is an apocalyptic number.

261155161344643 is a deficient number, since it is larger than the sum of its proper divisors (1).

261155161344643 is an equidigital number, since it uses as much as digits as its factorization.

261155161344643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6220800, while the sum is 52.

The spelling of 261155161344643 in words is "two hundred sixty-one trillion, one hundred fifty-five billion, one hundred sixty-one million, three hundred forty-four thousand, six hundred forty-three".