40809917 has 2 divisors, whose sum is σ = 40809918. Its totient is φ = 40809916.

The previous prime is 40809913. The next prime is 40809991. The reversal of 40809917 is 71990804.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 36893476 + 3916441 = 6074^2 + 1979^2 .

It is a cyclic number.

It is not a de Polignac number, because 40809917 - 2² = 40809913 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40809913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20404958 + 20404959.

It is an arithmetic number, because the mean of its divisors is an integer number (20404959).

Almost surely, 2^40809917 is an apocalyptic number.

It is an amenable number.

40809917 is a deficient number, since it is larger than the sum of its proper divisors (1).

40809917 is an equidigital number, since it uses as much as digits as its factorization.

40809917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 40809917 is about 6388.2640051895. The cubic root of 40809917 is about 344.2880142685.

The spelling of 40809917 in words is "forty million, eight hundred nine thousand, nine hundred seventeen".