161903 has 8 divisors (see below), whose sum is σ = 187680. Its totient is φ = 136800.

The previous prime is 161881. The next prime is 161911. The reversal of 161903 is 309161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161903 - 2⁶ = 161839 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 (161923) 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 7 ways as a sum of consecutive naturals, for example, 593 + ... + 821.

It is an arithmetic number, because the mean of its divisors is an integer number (23460).

2¹⁶¹⁹⁰³ is an apocalyptic number.

161903 is a deficient number, since it is larger than the sum of its proper divisors (25777).

161903 is a wasteful number, since it uses less digits than its factorization.

161903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337.

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

The square root of 161903 is about 402.3717186881. The cubic root of 161903 is about 54.5027353227.

The spelling of 161903 in words is "one hundred sixty-one thousand, nine hundred three".