161645 has 8 divisors (see below), whose sum is σ = 211680. Its totient is φ = 117520.

The previous prime is 161641. The next prime is 161659. The reversal of 161645 is 546161.

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

It is not a de Polignac number, because 161645 - 2² = 161641 is a prime.

It is a super-3 number, since 3×161645³ = 12670918030233375, which contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 161645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161641) 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, 1415 + ... + 1524.

It is an arithmetic number, because the mean of its divisors is an integer number (26460).

2¹⁶¹⁶⁴⁵ is an apocalyptic number.

It is an amenable number.

161645 is a deficient number, since it is larger than the sum of its proper divisors (50035).

161645 is a wasteful number, since it uses less digits than its factorization.

161645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2955.

The product of its digits is 720, while the sum is 23.

The square root of 161645 is about 402.0509917908. The cubic root of 161645 is about 54.4737690452.

It can be divided in two parts, 1616 and 45, that added together give a palindrome (1661).

The spelling of 161645 in words is "one hundred sixty-one thousand, six hundred forty-five".