190905 has 32 divisors (see below), whose sum is σ = 362880. Its totient is φ = 84480.

The previous prime is 190901. The next prime is 190909. The reversal of 190905 is 509091.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (190901) and next prime (190909).

It is not a de Polignac number, because 190905 - 2² = 190901 is a prime.

190905 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (190901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2101 + ... + 2189.

It is an arithmetic number, because the mean of its divisors is an integer number (11340).

2¹⁹⁰⁹⁰⁵ is an apocalyptic number.

190905 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

190905 is a deficient number, since it is larger than the sum of its proper divisors (171975).

190905 is a wasteful number, since it uses less digits than its factorization.

190905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121.

The product of its (nonzero) digits is 405, while the sum is 24.

The square root of 190905 is about 436.9267673192. The cubic root of 190905 is about 57.5801025989.

Adding to 190905 its reverse (509091), we get a palindrome (699996).

The spelling of 190905 in words is "one hundred ninety thousand, nine hundred five".