409399509 has 4 divisors (see below), whose sum is σ = 545866016. Its totient is φ = 272933004.

The previous prime is 409399499. The next prime is 409399511. The reversal of 409399509 is 905993904.

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 not a de Polignac number, because 409399509 - 2¹³ = 409391317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (409399519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68233249 + ... + 68233254.

It is an arithmetic number, because the mean of its divisors is an integer number (136466504).

Almost surely, 2^409399509 is an apocalyptic number.

It is an amenable number.

409399509 is a deficient number, since it is larger than the sum of its proper divisors (136466507).

409399509 is a wasteful number, since it uses less digits than its factorization.

409399509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136466506.

The product of its (nonzero) digits is 393660, while the sum is 48.

The square root of 409399509 is about 20233.6232296640. The cubic root of 409399509 is about 742.5330221457.

The spelling of 409399509 in words is "four hundred nine million, three hundred ninety-nine thousand, five hundred nine".