161939 has 4 divisors (see below), whose sum is σ = 164424. Its totient is φ = 159456.

The previous prime is 161923. The next prime is 161947. The reversal of 161939 is 939161.

161939 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 939161 = 211 ⋅4451.

It is a cyclic number.

It is not a de Polignac number, because 161939 - 2⁴ = 161923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1142 + ... + 1275.

It is an arithmetic number, because the mean of its divisors is an integer number (41106).

2¹⁶¹⁹³⁹ is an apocalyptic number.

161939 is a deficient number, since it is larger than the sum of its proper divisors (2485).

161939 is an equidigital number, since it uses as much as digits as its factorization.

161939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2484.

The product of its digits is 1458, while the sum is 29.

The square root of 161939 is about 402.4164509560. The cubic root of 161939 is about 54.5067746818.

The spelling of 161939 in words is "one hundred sixty-one thousand, nine hundred thirty-nine".