161849569 has 12 divisors (see below), whose sum is σ = 186216832. Its totient is φ = 137799000.

The previous prime is 161849563. The next prime is 161849587. The reversal of 161849569 is 965948161.

It is not a de Polignac number, because 161849569 - 2¹⁵ = 161816801 is a prime.

It is a super-2 number, since 2×161849569² = 52390565970971522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161849563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 440824 + ... + 441190.

Almost surely, 2^161849569 is an apocalyptic number.

It is an amenable number.

161849569 is a deficient number, since it is larger than the sum of its proper divisors (24367263).

161849569 is an frugal number, since it uses more digits than its factorization.

161849569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 876 (or 625 counting only the distinct ones).

The product of its digits is 466560, while the sum is 49.

The square root of 161849569 is about 12722.0112010641. The cubic root of 161849569 is about 544.9673902437.

The spelling of 161849569 in words is "one hundred sixty-one million, eight hundred forty-nine thousand, five hundred sixty-nine".