404442509 has 8 divisors (see below), whose sum is σ = 407235192. Its totient is φ = 401656320.

The previous prime is 404442503. The next prime is 404442517. The reversal of 404442509 is 905244404.

It can be written as a sum of positive squares in 4 ways, for example, as 25050025 + 379392484 = 5005^2 + 19478^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-404442509 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 (404442503) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 214997 + ... + 216869.

It is an arithmetic number, because the mean of its divisors is an integer number (50904399).

Almost surely, 2^404442509 is an apocalyptic number.

It is an amenable number.

404442509 is a deficient number, since it is larger than the sum of its proper divisors (2792683).

404442509 is a wasteful number, since it uses less digits than its factorization.

404442509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3247.

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 404442509 is about 20110.7560524213. The cubic root of 404442509 is about 739.5239871451.

The spelling of 404442509 in words is "four hundred four million, four hundred forty-two thousand, five hundred nine".