40001 has 8 divisors (see below), whose sum is σ = 45864. Its totient is φ = 34560.

The previous prime is 39989. The next prime is 40009. The reversal of 40001 is 10004.

40001 = 26² + 27² + ... + 51².

It is a Cunningham number, because it is equal to 200²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 1 + 40000 = 1^2 + 200^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 40001 - 2⁶ = 39937 is a prime.

It is a magnanimous number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40009) 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, 131 + ... + 311.

It is an arithmetic number, because the mean of its divisors is an integer number (5733).

2⁴⁰⁰⁰¹ is an apocalyptic number.

It is an amenable number.

40001 is a deficient number, since it is larger than the sum of its proper divisors (5863).

40001 is a wasteful number, since it uses less digits than its factorization.

40001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211.

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 40001 is about 200.0024999844. The cubic root of 40001 is about 34.1998039272.

Adding to 40001 its reverse (10004), we get a palindrome (50005).

The spelling of 40001 in words is "forty thousand, one", and thus it is an iban number.