40251209 has 2 divisors, whose sum is σ = 40251210. Its totient is φ = 40251208.

The previous prime is 40251187. The next prime is 40251241. The reversal of 40251209 is 90215204.

40251209 is nontrivially palindromic in base 14.

40251209 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30030400 + 10220809 = 5480^2 + 3197^2 .

It is a cyclic number.

It is not a de Polignac number, because 40251209 - 2⁸ = 40250953 is a prime.

It is not a weakly prime, because it can be changed into another prime (40251269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20125604 + 20125605.

It is an arithmetic number, because the mean of its divisors is an integer number (20125605).

Almost surely, 2^40251209 is an apocalyptic number.

It is an amenable number.

40251209 is a deficient number, since it is larger than the sum of its proper divisors (1).

40251209 is an equidigital number, since it uses as much as digits as its factorization.

40251209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 40251209 is about 6344.3840520574. The cubic root of 40251209 is about 342.7096313765.

The spelling of 40251209 in words is "forty million, two hundred fifty-one thousand, two hundred nine".