161599549 has 2 divisors, whose sum is σ = 161599550. Its totient is φ = 161599548.

The previous prime is 161599531. The next prime is 161599577. The reversal of 161599549 is 945995161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82264900 + 79334649 = 9070^2 + 8907^2 .

It is a cyclic number.

It is not a de Polignac number, because 161599549 - 2¹³ = 161591357 is a prime.

It is a super-2 number, since 2×161599549² = 52228828474006802, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161599519) 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, 80799774 + 80799775.

It is an arithmetic number, because the mean of its divisors is an integer number (80799775).

Almost surely, 2^161599549 is an apocalyptic number.

It is an amenable number.

161599549 is a deficient number, since it is larger than the sum of its proper divisors (1).

161599549 is an equidigital number, since it uses as much as digits as its factorization.

161599549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 437400, while the sum is 49.

The square root of 161599549 is about 12712.1811267776. The cubic root of 161599549 is about 544.6866296015.

The spelling of 161599549 in words is "one hundred sixty-one million, five hundred ninety-nine thousand, five hundred forty-nine".