203981 has 6 divisors (see below), whose sum is σ = 211050. Its totient is φ = 197136.

The previous prime is 203977. The next prime is 203989. The reversal of 203981 is 189302.

It can be written as a sum of positive squares in 3 ways, for example, as 70756 + 133225 = 266^2 + 365^2 .

It is not a de Polignac number, because 203981 - 2² = 203977 is a prime.

It is a super-2 number, since 2×203981² = 83216496722, 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 203981.

It is not an unprimeable number, because it can be changed into a prime (203989) 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, 1295 + ... + 1443.

It is an arithmetic number, because the mean of its divisors is an integer number (35175).

2²⁰³⁹⁸¹ is an apocalyptic number.

It is an amenable number.

203981 is a deficient number, since it is larger than the sum of its proper divisors (7069).

203981 is an equidigital number, since it uses as much as digits as its factorization.

203981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 223 (or 186 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 203981 is about 451.6425577821. The cubic root of 203981 is about 58.8658255216.

The spelling of 203981 in words is "two hundred three thousand, nine hundred eighty-one".