309161 has 4 divisors (see below), whose sum is σ = 312324. Its totient is φ = 306000.

The previous prime is 309157. The next prime is 309167. The reversal of 309161 is 161903.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 13225 = 544^2 + 115^2 .

It is a cyclic number.

It is not a de Polignac number, because 309161 - 2² = 309157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (309167) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1430 + ... + 1631.

It is an arithmetic number, because the mean of its divisors is an integer number (78081).

2³⁰⁹¹⁶¹ is an apocalyptic number.

It is an amenable number.

309161 is a deficient number, since it is larger than the sum of its proper divisors (3163).

309161 is a wasteful number, since it uses less digits than its factorization.

309161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3162.

The product of its (nonzero) digits is 162, while the sum is 20.

The square root of 309161 is about 556.0224815599. The cubic root of 309161 is about 67.6178827145.

The spelling of 309161 in words is "three hundred nine thousand, one hundred sixty-one".