161545222273 has 16 divisors (see below), whose sum is σ = 164719740240. Its totient is φ = 158406183936.

The previous prime is 161545222217. The next prime is 161545222301. The reversal of 161545222273 is 372222545161.

It can be written as a sum of positive squares in 8 ways, for example, as 2082370689 + 159462851584 = 45633^2 + 399328^2 .

It is a cyclic number.

It is not a de Polignac number, because 161545222273 - 2²⁵ = 161511667841 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161545222673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5473111 + ... + 5502547.

It is an arithmetic number, because the mean of its divisors is an integer number (10294983765).

Almost surely, 2^161545222273 is an apocalyptic number.

It is an amenable number.

161545222273 is a deficient number, since it is larger than the sum of its proper divisors (3174517967).

161545222273 is a wasteful number, since it uses less digits than its factorization.

161545222273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30036.

The product of its digits is 201600, while the sum is 40.

The spelling of 161545222273 in words is "one hundred sixty-one billion, five hundred forty-five million, two hundred twenty-two thousand, two hundred seventy-three".