40635209 has 2 divisors, whose sum is σ = 40635210. Its totient is φ = 40635208.

The previous prime is 40635197. The next prime is 40635233. The reversal of 40635209 is 90253604.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31393609 + 9241600 = 5603^2 + 3040^2 .

It is a cyclic number.

It is not a de Polignac number, because 40635209 - 2⁴ = 40635193 is a prime.

It is not a weakly prime, because it can be changed into another prime (40632209) 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, 20317604 + 20317605.

It is an arithmetic number, because the mean of its divisors is an integer number (20317605).

Almost surely, 2^40635209 is an apocalyptic number.

It is an amenable number.

40635209 is a deficient number, since it is larger than the sum of its proper divisors (1).

40635209 is an equidigital number, since it uses as much as digits as its factorization.

40635209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 40635209 is about 6374.5752015330. The cubic root of 40635209 is about 343.7960104143.

The spelling of 40635209 in words is "forty million, six hundred thirty-five thousand, two hundred nine".