161281387523 has 2 divisors, whose sum is σ = 161281387524. Its totient is φ = 161281387522.

The previous prime is 161281387511. The next prime is 161281387537. The reversal of 161281387523 is 325783182161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161281387523 - 2⁴ = 161281387507 is a prime.

It is a super-2 number, since 2×161281387523² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161281387823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80640693761 + 80640693762.

It is an arithmetic number, because the mean of its divisors is an integer number (80640693762).

Almost surely, 2^161281387523 is an apocalyptic number.

161281387523 is a deficient number, since it is larger than the sum of its proper divisors (1).

161281387523 is an equidigital number, since it uses as much as digits as its factorization.

161281387523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 483840, while the sum is 47.

The spelling of 161281387523 in words is "one hundred sixty-one billion, two hundred eighty-one million, three hundred eighty-seven thousand, five hundred twenty-three".