189611809 has 4 divisors (see below), whose sum is σ = 192441904. Its totient is φ = 186781716.

The previous prime is 189611803. The next prime is 189611813. The reversal of 189611809 is 908116981.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 908116981 = 23 ⋅39483347.

It is a cyclic number.

It is not a de Polignac number, because 189611809 - 2³ = 189611801 is a prime.

It is a super-2 number, since 2×189611809² = 71905276224504962, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (189611801) 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, 1414947 + ... + 1415080.

It is an arithmetic number, because the mean of its divisors is an integer number (48110476).

Almost surely, 2^189611809 is an apocalyptic number.

It is an amenable number.

189611809 is a deficient number, since it is larger than the sum of its proper divisors (2830095).

189611809 is an equidigital number, since it uses as much as digits as its factorization.

189611809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2830094.

The product of its (nonzero) digits is 31104, while the sum is 43.

The square root of 189611809 is about 13769.9603848377. The cubic root of 189611809 is about 574.4979198799.

The spelling of 189611809 in words is "one hundred eighty-nine million, six hundred eleven thousand, eight hundred nine".