40291 has 4 divisors (see below), whose sum is σ = 41272. Its totient is φ = 39312.

The previous prime is 40289. The next prime is 40343. The reversal of 40291 is 19204.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 40291 - 2¹ = 40289 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40231) 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, 426 + ... + 511.

It is an arithmetic number, because the mean of its divisors is an integer number (10318).

2⁴⁰²⁹¹ is an apocalyptic number.

40291 is a deficient number, since it is larger than the sum of its proper divisors (981).

40291 is an equidigital number, since it uses as much as digits as its factorization.

40291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 40291 is about 200.7261816505. The cubic root of 40291 is about 34.2822524613.

Adding to 40291 its reverse (19204), we get a palindrome (59495).

The spelling of 40291 in words is "forty thousand, two hundred ninety-one".