40217909 has 2 divisors, whose sum is σ = 40217910. Its totient is φ = 40217908.

The previous prime is 40217833. The next prime is 40217923. The reversal of 40217909 is 90971204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37478884 + 2739025 = 6122^2 + 1655^2 .

It is a cyclic number.

It is not a de Polignac number, because 40217909 - 2¹⁶ = 40152373 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40217929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20108954 + 20108955.

It is an arithmetic number, because the mean of its divisors is an integer number (20108955).

Almost surely, 2^40217909 is an apocalyptic number.

It is an amenable number.

40217909 is a deficient number, since it is larger than the sum of its proper divisors (1).

40217909 is an equidigital number, since it uses as much as digits as its factorization.

40217909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 40217909 is about 6341.7591408063. The cubic root of 40217909 is about 342.6150969134.

The spelling of 40217909 in words is "forty million, two hundred seventeen thousand, nine hundred nine".