203681 has 4 divisors (see below), whose sum is σ = 204612. Its totient is φ = 202752.

The previous prime is 203669. The next prime is 203713. The reversal of 203681 is 186302.

203681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 186302 = 2 ⋅93151.

It can be written as a sum of positive squares in 2 ways, for example, as 160000 + 43681 = 400^2 + 209^2 .

It is a cyclic number.

It is not a de Polignac number, because 203681 - 2⁶ = 203617 is a prime.

It is a super-2 number, since 2×203681² = 82971899522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 203681.

It is not an unprimeable number, because it can be changed into a prime (203641) 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, 65 + ... + 641.

It is an arithmetic number, because the mean of its divisors is an integer number (51153).

2²⁰³⁶⁸¹ is an apocalyptic number.

It is an amenable number.

203681 is a deficient number, since it is larger than the sum of its proper divisors (931).

203681 is an equidigital number, since it uses as much as digits as its factorization.

203681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 930.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 203681 is about 451.3103145287. The cubic root of 203681 is about 58.8369528777.

Adding to 203681 its reverse (186302), we get a palindrome (389983).

The spelling of 203681 in words is "two hundred three thousand, six hundred eighty-one".