161390173 has 12 divisors (see below), whose sum is σ = 188221980. Its totient is φ = 137979072.

The previous prime is 161390167. The next prime is 161390179. The reversal of 161390173 is 371093161.

It is an interprime number because it is at equal distance from previous prime (161390167) and next prime (161390179).

It can be written as a sum of positive squares in 2 ways, for example, as 137311524 + 24078649 = 11718^2 + 4907^2 .

It is not a de Polignac number, because 161390173 - 2⁹ = 161389661 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161390179) 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 11 ways as a sum of consecutive naturals, for example, 16015 + ... + 24067.

It is an arithmetic number, because the mean of its divisors is an integer number (15685165).

Almost surely, 2^161390173 is an apocalyptic number.

It is an amenable number.

161390173 is a deficient number, since it is larger than the sum of its proper divisors (26831807).

161390173 is an equidigital number, since it uses as much as digits as its factorization.

161390173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8476 (or 8469 counting only the distinct ones).

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 161390173 is about 12703.9432067370. The cubic root of 161390173 is about 544.4512873668.

The spelling of 161390173 in words is "one hundred sixty-one million, three hundred ninety thousand, one hundred seventy-three".