194128489 has 3 divisors (see below), whose sum is σ = 194142423. Its totient is φ = 194114556.

The previous prime is 194128477. The next prime is 194128499. The reversal of 194128489 is 984821491.

The square root of 194128489 is 13933.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 984821491 = 2137 ⋅460843.

It can be written as a sum of positive squares in only one way, i.e., 193627225 + 501264 = 13915^2 + 708^2 .

It is not a de Polignac number, because 194128489 - 2⁹ = 194127977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (194128499) 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 2 ways as a sum of consecutive naturals, for example, 6967 + ... + 20899.

It is an arithmetic number, because the mean of its divisors is an integer number (64714141).

Almost surely, 2^194128489 is an apocalyptic number.

194128489 is the 13933-rd square number.

194128489 is the 6967-th centered octagonal number.

It is an amenable number.

194128489 is a deficient number, since it is larger than the sum of its proper divisors (13934).

194128489 is an frugal number, since it uses more digits than its factorization.

194128489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27866 (or 13933 counting only the distinct ones).

The product of its digits is 165888, while the sum is 46.

The cubic root of 194128489 is about 579.0238127347.

The spelling of 194128489 in words is "one hundred ninety-four million, one hundred twenty-eight thousand, four hundred eighty-nine".