195138889 has 4 divisors (see below), whose sum is σ = 212878800. Its totient is φ = 177398980.

The previous prime is 195138887. The next prime is 195138913. The reversal of 195138889 is 988831591.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 988831591 = 11 ⋅89893781.

It is not a de Polignac number, because 195138889 - 2¹ = 195138887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195138887) 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 3 ways as a sum of consecutive naturals, for example, 8869939 + ... + 8869960.

It is an arithmetic number, because the mean of its divisors is an integer number (53219700).

Almost surely, 2^195138889 is an apocalyptic number.

It is an amenable number.

195138889 is a deficient number, since it is larger than the sum of its proper divisors (17739911).

195138889 is a wasteful number, since it uses less digits than its factorization.

195138889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17739910.

The product of its digits is 622080, while the sum is 52.

The square root of 195138889 is about 13969.2121825105. The cubic root of 195138889 is about 580.0266426525.

The spelling of 195138889 in words is "one hundred ninety-five million, one hundred thirty-eight thousand, eight hundred eighty-nine".