194128281 has 24 divisors (see below), whose sum is σ = 284731200. Its totient is φ = 127439136.

The previous prime is 194128267. The next prime is 194128289. The reversal of 194128281 is 182821491.

It is a happy number.

It is not a de Polignac number, because 194128281 - 2⁶ = 194128217 is a prime.

It is a super-2 number, since 2×194128281² = 75371578968029922, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (194128289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 191131 + ... + 192143.

It is an arithmetic number, because the mean of its divisors is an integer number (11863800).

Almost surely, 2^194128281 is an apocalyptic number.

It is an amenable number.

194128281 is a deficient number, since it is larger than the sum of its proper divisors (90602919).

194128281 is a wasteful number, since it uses less digits than its factorization.

194128281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1325 (or 1322 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 194128281 is about 13932.9925357046. The cubic root of 194128281 is about 579.0236059353.

The spelling of 194128281 in words is "one hundred ninety-four million, one hundred twenty-eight thousand, two hundred eighty-one".