40749809 has 2 divisors, whose sum is σ = 40749810. Its totient is φ = 40749808.

The previous prime is 40749803. The next prime is 40749817. The reversal of 40749809 is 90894704.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 35664784 + 5085025 = 5972^2 + 2255^2 .

It is a cyclic number.

It is not a de Polignac number, because 40749809 - 2²⁴ = 23972593 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (40749803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20374904 + 20374905.

It is an arithmetic number, because the mean of its divisors is an integer number (20374905).

Almost surely, 2^40749809 is an apocalyptic number.

It is an amenable number.

40749809 is a deficient number, since it is larger than the sum of its proper divisors (1).

40749809 is an equidigital number, since it uses as much as digits as its factorization.

40749809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 40749809 is about 6383.5577071097. The cubic root of 40749809 is about 344.1188998804.

The spelling of 40749809 in words is "forty million, seven hundred forty-nine thousand, eight hundred nine".