40408213 has 2 divisors, whose sum is σ = 40408214. Its totient is φ = 40408212.

The previous prime is 40408211. The next prime is 40408237. The reversal of 40408213 is 31280404.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36881329 + 3526884 = 6073^2 + 1878^2 .

It is a cyclic number.

It is not a de Polignac number, because 40408213 - 2¹ = 40408211 is a prime.

Together with 40408211, it forms a pair of twin primes.

It is a zygodrome in base 3.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40408211) 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, 20204106 + 20204107.

It is an arithmetic number, because the mean of its divisors is an integer number (20204107).

Almost surely, 2^40408213 is an apocalyptic number.

It is an amenable number.

40408213 is a deficient number, since it is larger than the sum of its proper divisors (1).

40408213 is an equidigital number, since it uses as much as digits as its factorization.

40408213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 40408213 is about 6356.7454723309. The cubic root of 40408213 is about 343.1546447137.

Adding to 40408213 its reverse (31280404), we get a palindrome (71688617).

The spelling of 40408213 in words is "forty million, four hundred eight thousand, two hundred thirteen".