161545281 has 12 divisors (see below), whose sum is σ = 220526928. Its totient is φ = 105188664.

The previous prime is 161545273. The next prime is 161545297. The reversal of 161545281 is 182545161.

It is not a de Polignac number, because 161545281 - 2³ = 161545273 is a prime.

It is a super-2 number, since 2×161545281² = 52193755626737922, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161545211) 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, 9015 + ... + 20108.

It is an arithmetic number, because the mean of its divisors is an integer number (18377244).

Almost surely, 2^161545281 is an apocalyptic number.

It is an amenable number.

161545281 is a deficient number, since it is larger than the sum of its proper divisors (58981647).

161545281 is an equidigital number, since it uses as much as digits as its factorization.

161545281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29212 (or 29169 counting only the distinct ones).

The product of its digits is 9600, while the sum is 33.

The square root of 161545281 is about 12710.0464593958. The cubic root of 161545281 is about 544.6256509588.

The spelling of 161545281 in words is "one hundred sixty-one million, five hundred forty-five thousand, two hundred eighty-one".