40003 has 4 divisors (see below), whose sum is σ = 40480. Its totient is φ = 39528.

The previous prime is 39989. The next prime is 40009. The reversal of 40003 is 30004.

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.

It is a cyclic number.

It is not a de Polignac number, because 40003 - 2⁵ = 39971 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 75 + ... + 292.

It is an arithmetic number, because the mean of its divisors is an integer number (10120).

2⁴⁰⁰⁰³ is an apocalyptic number.

40003 is a deficient number, since it is larger than the sum of its proper divisors (477).

40003 is a wasteful number, since it uses less digits than its factorization.

40003 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 476.

The product of its (nonzero) digits is 12, while the sum is 7.

The square root of 40003 is about 200.0074998594. The cubic root of 40003 is about 34.2003739001.

Adding to 40003 its reverse (30004), we get a palindrome (70007).

Subtracting from 40003 its reverse (30004), we obtain a palindrome (9999).

The spelling of 40003 in words is "forty thousand, three", and thus it is an iban number.