40019909 has 4 divisors (see below), whose sum is σ = 42126240. Its totient is φ = 37913580.

The previous prime is 40019897. The next prime is 40019911. The reversal of 40019909 is 90991004.

40019909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40019909 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40019939) 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 in 3 ways as a sum of consecutive naturals, for example, 1053137 + ... + 1053174.

It is an arithmetic number, because the mean of its divisors is an integer number (10531560).

Almost surely, 2^40019909 is an apocalyptic number.

It is an amenable number.

40019909 is a deficient number, since it is larger than the sum of its proper divisors (2106331).

40019909 is a wasteful number, since it uses less digits than its factorization.

40019909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2106330.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 40019909 is about 6326.1290691860. The cubic root of 40019909 is about 342.0519197762.

The spelling of 40019909 in words is "forty million, nineteen thousand, nine hundred nine".