161709 has 8 divisors (see below), whose sum is σ = 227040. Its totient is φ = 102096.

The previous prime is 161683. The next prime is 161717. The reversal of 161709 is 907161.

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

It is not a de Polignac number, because 161709 - 2⁸ = 161453 is a prime.

It is a super-2 number, since 2×161709² = 52299601362, which contains 22 as substring.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1362 + ... + 1475.

It is an arithmetic number, because the mean of its divisors is an integer number (28380).

2¹⁶¹⁷⁰⁹ is an apocalyptic number.

161709 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

It is an amenable number.

161709 is a deficient number, since it is larger than the sum of its proper divisors (65331).

161709 is a wasteful number, since it uses less digits than its factorization.

161709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859.

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 161709 is about 402.1305758084. The cubic root of 161709 is about 54.4809573513.

It can be divided in two parts, 16170 and 9, that multiplied together give a triangular number (145530 = T₅₃₉).

The spelling of 161709 in words is "one hundred sixty-one thousand, seven hundred nine".