161105281 has 2 divisors, whose sum is σ = 161105282. Its totient is φ = 161105280.

The previous prime is 161105251. The next prime is 161105291. The reversal of 161105281 is 182501161.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121352256 + 39753025 = 11016^2 + 6305^2 .

It is an emirp because it is prime and its reverse (182501161) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 161105281 - 2⁵ = 161105249 is a prime.

It is a super-2 number, since 2×161105281² = 51909823132177922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (161105251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80552640 + 80552641.

It is an arithmetic number, because the mean of its divisors is an integer number (80552641).

Almost surely, 2^161105281 is an apocalyptic number.

It is an amenable number.

161105281 is a deficient number, since it is larger than the sum of its proper divisors (1).

161105281 is an equidigital number, since it uses as much as digits as its factorization.

161105281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 25.

The square root of 161105281 is about 12692.7255150342. The cubic root of 161105281 is about 544.1307367173.

The spelling of 161105281 in words is "one hundred sixty-one million, one hundred five thousand, two hundred eighty-one".