194478109 has 6 divisors (see below), whose sum is σ = 226229694. Its totient is φ = 166695480.

The previous prime is 194478061. The next prime is 194478131. The reversal of 194478109 is 901874491.

It can be written as a sum of positive squares in only one way, i.e., 190357209 + 4120900 = 13797^2 + 2030^2 .

It is not a de Polignac number, because 194478109 - 2¹³ = 194469917 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (194478169) 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 5 ways as a sum of consecutive naturals, for example, 1984422 + ... + 1984519.

It is an arithmetic number, because the mean of its divisors is an integer number (37704949).

Almost surely, 2^194478109 is an apocalyptic number.

It is an amenable number.

194478109 is a deficient number, since it is larger than the sum of its proper divisors (31751585).

194478109 is an equidigital number, since it uses as much as digits as its factorization.

194478109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3968955 (or 3968948 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 194478109 is about 13945.5408285229. The cubic root of 194478109 is about 579.3712061876.

It can be divided in two parts, 19447 and 8109, that added together give a square (27556 = 166²).

The spelling of 194478109 in words is "one hundred ninety-four million, four hundred seventy-eight thousand, one hundred nine".