161105491 has 2 divisors, whose sum is σ = 161105492. Its totient is φ = 161105490.

The previous prime is 161105479. The next prime is 161105521. The reversal of 161105491 is 194501161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161105491 - 2¹⁷ = 160974419 is a prime.

It is not a weakly prime, because it can be changed into another prime (161105471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80552745 + 80552746.

It is an arithmetic number, because the mean of its divisors is an integer number (80552746).

Almost surely, 2^161105491 is an apocalyptic number.

161105491 is a deficient number, since it is larger than the sum of its proper divisors (1).

161105491 is an equidigital number, since it uses as much as digits as its factorization.

161105491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 28.

The square root of 161105491 is about 12692.7337874864. The cubic root of 161105491 is about 544.1309731411.

It can be divided in two parts, 161105 and 491, that added together give a triangular number (161596 = T₅₆₈).

The spelling of 161105491 in words is "one hundred sixty-one million, one hundred five thousand, four hundred ninety-one".