161281387511 has 2 divisors, whose sum is σ = 161281387512. Its totient is φ = 161281387510.

The previous prime is 161281387507. The next prime is 161281387523. The reversal of 161281387511 is 115783182161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161281387511 - 2² = 161281387507 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161281387541) 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 as a sum of consecutive naturals, namely, 80640693755 + 80640693756.

It is an arithmetic number, because the mean of its divisors is an integer number (80640693756).

Almost surely, 2^161281387511 is an apocalyptic number.

161281387511 is a deficient number, since it is larger than the sum of its proper divisors (1).

161281387511 is an equidigital number, since it uses as much as digits as its factorization.

161281387511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 80640, while the sum is 44.

The spelling of 161281387511 in words is "one hundred sixty-one billion, two hundred eighty-one million, three hundred eighty-seven thousand, five hundred eleven".