40099909 has 2 divisors, whose sum is σ = 40099910. Its totient is φ = 40099908.

The previous prime is 40099907. The next prime is 40099921. The reversal of 40099909 is 90999004.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39727809 + 372100 = 6303^2 + 610^2 .

It is a cyclic number.

It is not a de Polignac number, because 40099909 - 2¹ = 40099907 is a prime.

Together with 40099907, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40099903) 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, 20049954 + 20049955.

It is an arithmetic number, because the mean of its divisors is an integer number (20049955).

Almost surely, 2^40099909 is an apocalyptic number.

It is an amenable number.

40099909 is a deficient number, since it is larger than the sum of its proper divisors (1).

40099909 is an equidigital number, since it uses as much as digits as its factorization.

40099909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26244, while the sum is 40.

The square root of 40099909 is about 6332.4488943852. The cubic root of 40099909 is about 342.2796892439.

The spelling of 40099909 in words is "forty million, ninety-nine thousand, nine hundred nine".