195878639 has 4 divisors (see below), whose sum is σ = 213685800. Its totient is φ = 178071480.

The previous prime is 195878623. The next prime is 195878647. The reversal of 195878639 is 936878591.

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

It is a cyclic number.

It is not a de Polignac number, because 195878639 - 2⁴ = 195878623 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 (195872639) 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, 8903564 + ... + 8903585.

It is an arithmetic number, because the mean of its divisors is an integer number (53421450).

Almost surely, 2^195878639 is an apocalyptic number.

195878639 is a deficient number, since it is larger than the sum of its proper divisors (17807161).

195878639 is a wasteful number, since it uses less digits than its factorization.

195878639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17807160.

The product of its digits is 3265920, while the sum is 56.

The square root of 195878639 is about 13995.6650074228. The cubic root of 195878639 is about 580.7586574386.

The spelling of 195878639 in words is "one hundred ninety-five million, eight hundred seventy-eight thousand, six hundred thirty-nine".