190909 has 2 divisors, whose sum is σ = 190910. Its totient is φ = 190908.

The previous prime is 190901. The next prime is 190913. The reversal of 190909 is 909091.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152100 + 38809 = 390^2 + 197^2 .

It is an emirp because it is prime and its reverse (909091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 190909 - 2³ = 190901 is a prime.

190909 is a modest number, since divided by 909 gives 19 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (190901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95454 + 95455.

It is an arithmetic number, because the mean of its divisors is an integer number (95455).

2¹⁹⁰⁹⁰⁹ is an apocalyptic number.

It is an amenable number.

190909 is a deficient number, since it is larger than the sum of its proper divisors (1).

190909 is an equidigital number, since it uses as much as digits as its factorization.

190909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 729, while the sum is 28.

The square root of 190909 is about 436.9313447213. The cubic root of 190909 is about 57.5805047514.

The spelling of 190909 in words is "one hundred ninety thousand, nine hundred nine".