195778189 has 4 divisors (see below), whose sum is σ = 198460156. Its totient is φ = 193096224.

The previous prime is 195778151. The next prime is 195778201. The reversal of 195778189 is 981877591.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76422564 + 119355625 = 8742^2 + 10925^2 .

It is a cyclic number.

It is not a de Polignac number, because 195778189 - 2¹⁹ = 195253901 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 (195778789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1340874 + ... + 1341019.

It is an arithmetic number, because the mean of its divisors is an integer number (49615039).

Almost surely, 2^195778189 is an apocalyptic number.

It is an amenable number.

195778189 is a deficient number, since it is larger than the sum of its proper divisors (2681967).

195778189 is an equidigital number, since it uses as much as digits as its factorization.

195778189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2681966.

The product of its digits is 1270080, while the sum is 55.

The square root of 195778189 is about 13992.0759360432. The cubic root of 195778189 is about 580.6593660569.

The spelling of 195778189 in words is "one hundred ninety-five million, seven hundred seventy-eight thousand, one hundred eighty-nine".