163641 has 4 divisors (see below), whose sum is σ = 218192. Its totient is φ = 109092.

The previous prime is 163637. The next prime is 163643. The reversal of 163641 is 146361.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 146361 = 3 ⋅48787.

It is not a de Polignac number, because 163641 - 2² = 163637 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (163643) 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, 27271 + ... + 27276.

It is an arithmetic number, because the mean of its divisors is an integer number (54548).

2¹⁶³⁶⁴¹ is an apocalyptic number.

It is an amenable number.

163641 is a deficient number, since it is larger than the sum of its proper divisors (54551).

163641 is an equidigital number, since it uses as much as digits as its factorization.

163641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54550.

The product of its digits is 432, while the sum is 21.

The square root of 163641 is about 404.5256481362. The cubic root of 163641 is about 54.6970673329.

It can be divided in two parts, 1636 and 41, that multiplied together give a palindrome (67076).

The spelling of 163641 in words is "one hundred sixty-three thousand, six hundred forty-one".