40381 has 4 divisors (see below), whose sum is σ = 44064. Its totient is φ = 36700.

The previous prime is 40361. The next prime is 40387. The reversal of 40381 is 18304.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40381 - 2⁷ = 40253 is a prime.

It is a super-2 number, since 2×40381² = 3261250322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1825 + ... + 1846.

It is an arithmetic number, because the mean of its divisors is an integer number (11016).

2⁴⁰³⁸¹ is an apocalyptic number.

It is an amenable number.

40381 is a deficient number, since it is larger than the sum of its proper divisors (3683).

40381 is a wasteful number, since it uses less digits than its factorization.

40381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3682.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 40381 is about 200.9502425975. The cubic root of 40381 is about 34.3077594664.

Adding to 40381 its reverse (18304), we get a palindrome (58685).

It can be divided in two parts, 403 and 81, that added together give a palindrome (484).

The spelling of 40381 in words is "forty thousand, three hundred eighty-one".