161749 has 6 divisors (see below), whose sum is σ = 188214. Its totient is φ = 138600.

The previous prime is 161743. The next prime is 161753. The reversal of 161749 is 947161.

It can be written as a sum of positive squares in only one way, i.e., 117649 + 44100 = 343^2 + 210^2 .

It is not a de Polignac number, because 161749 - 2³ = 161741 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 (161741) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1602 + ... + 1699.

It is an arithmetic number, because the mean of its divisors is an integer number (31369).

2¹⁶¹⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

161749 is a deficient number, since it is larger than the sum of its proper divisors (26465).

161749 is an equidigital number, since it uses as much as digits as its factorization.

161749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3315 (or 3308 counting only the distinct ones).

The product of its digits is 1512, while the sum is 28.

The square root of 161749 is about 402.1803078223. The cubic root of 161749 is about 54.4854490795.

The spelling of 161749 in words is "one hundred sixty-one thousand, seven hundred forty-nine".