190809 has 16 divisors (see below), whose sum is σ = 291840. Its totient is φ = 123120.

The previous prime is 190807. The next prime is 190811. The reversal of 190809 is 908091.

It is an interprime number because it is at equal distance from previous prime (190807) and next prime (190811).

It is not a de Polignac number, because 190809 - 2¹ = 190807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

190809 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (190807) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 904 + ... + 1094.

It is an arithmetic number, because the mean of its divisors is an integer number (18240).

2¹⁹⁰⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

190809 is a deficient number, since it is larger than the sum of its proper divisors (101031).

190809 is a wasteful number, since it uses less digits than its factorization.

190809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 190809 is about 436.8168952776. The cubic root of 190809 is about 57.5704492518.

It can be divided in two parts, 190 and 809, that added together give a palindrome (999).

The spelling of 190809 in words is "one hundred ninety thousand, eight hundred nine".