40813 has 2 divisors, whose sum is σ = 40814. Its totient is φ = 40812.

The previous prime is 40801. The next prime is 40819. The reversal of 40813 is 31804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 40804 + 9 = 202^2 + 3^2 .

It is a cyclic number.

It is not a de Polignac number, because 40813 - 2¹³ = 32621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40819) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20406 + 20407.

It is an arithmetic number, because the mean of its divisors is an integer number (20407).

2⁴⁰⁸¹³ is an apocalyptic number.

It is an amenable number.

40813 is a deficient number, since it is larger than the sum of its proper divisors (1).

40813 is an equidigital number, since it uses as much as digits as its factorization.

40813 is an odious number, because the sum of its binary digits is odd.

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

The square root of 40813 is about 202.0222759995. The cubic root of 40813 is about 34.4296683838.

Subtracting from 40813 its reverse (31804), we obtain a palindrome (9009).

The spelling of 40813 in words is "forty thousand, eight hundred thirteen".