190711809 has 18 divisors (see below), whose sum is σ = 277743830. Its totient is φ = 126101376.

The previous prime is 190711769. The next prime is 190711811. The reversal of 190711809 is 908117091.

It can be written as a sum of positive squares in 3 ways, for example, as 10400625 + 180311184 = 3225^2 + 13428^2 .

It is not a de Polignac number, because 190711809 - 2²⁰ = 189663233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (190711879) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 168357 + ... + 169485.

Almost surely, 2^190711809 is an apocalyptic number.

It is an amenable number.

190711809 is a deficient number, since it is larger than the sum of its proper divisors (87032021).

190711809 is a wasteful number, since it uses less digits than its factorization.

190711809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1409 (or 1269 counting only the distinct ones).

The product of its (nonzero) digits is 4536, while the sum is 36.

The square root of 190711809 is about 13809.8446406902. The cubic root of 190711809 is about 575.6067284393.

The spelling of 190711809 in words is "one hundred ninety million, seven hundred eleven thousand, eight hundred nine".