40981 has 4 divisors (see below), whose sum is σ = 41472. Its totient is φ = 40492.

The previous prime is 40973. The next prime is 40993. The reversal of 40981 is 18904.

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, 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 40981 - 2³ = 40973 is a prime.

It is a super-2 number, since 2×40981² = 3358884722, which contains 22 as substring.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

40981 is a lucky number.

It is a nialpdrome in base 15.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85 + ... + 298.

It is an arithmetic number, because the mean of its divisors is an integer number (10368).

2⁴⁰⁹⁸¹ is an apocalyptic number.

It is an amenable number.

40981 is a deficient number, since it is larger than the sum of its proper divisors (491).

40981 is a wasteful number, since it uses less digits than its factorization.

40981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 490.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 40981 is about 202.4376447205. The cubic root of 40981 is about 34.4768450664.

The spelling of 40981 in words is "forty thousand, nine hundred eighty-one".