40091813 has 2 divisors, whose sum is σ = 40091814. Its totient is φ = 40091812.

The previous prime is 40091791. The next prime is 40091827. The reversal of 40091813 is 31819004.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 32512804 + 7579009 = 5702^2 + 2753^2 .

It is a cyclic number.

It is not a de Polignac number, because 40091813 - 2¹⁶ = 40026277 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40091873) 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 as a sum of consecutive naturals, namely, 20045906 + 20045907.

It is an arithmetic number, because the mean of its divisors is an integer number (20045907).

Almost surely, 2^40091813 is an apocalyptic number.

It is an amenable number.

40091813 is a deficient number, since it is larger than the sum of its proper divisors (1).

40091813 is an equidigital number, since it uses as much as digits as its factorization.

40091813 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 40091813 is about 6331.8096149521. The cubic root of 40091813 is about 342.2566527587.

It can be divided in two parts, 40091 and 813, that added together give a palindrome (40904).

The spelling of 40091813 in words is "forty million, ninety-one thousand, eight hundred thirteen".