1909509473 has 4 divisors (see below), whose sum is σ = 1992531648. Its totient is φ = 1826487300.

The previous prime is 1909509461. The next prime is 1909509491. The reversal of 1909509473 is 3749059091.

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 not a de Polignac number, because 1909509473 - 2⁴ = 1909509457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1909509403) 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, 41511053 + ... + 41511098.

It is an arithmetic number, because the mean of its divisors is an integer number (498132912).

Almost surely, 2^1909509473 is an apocalyptic number.

It is an amenable number.

1909509473 is a deficient number, since it is larger than the sum of its proper divisors (83022175).

1909509473 is an equidigital number, since it uses as much as digits as its factorization.

1909509473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 83022174.

The product of its (nonzero) digits is 306180, while the sum is 47.

The square root of 1909509473 is about 43697.9344248673. The cubic root of 1909509473 is about 1240.6252208211.

The spelling of 1909509473 in words is "one billion, nine hundred nine million, five hundred nine thousand, four hundred seventy-three".