195312521291 has 4 divisors (see below), whose sum is σ = 195318053784. Its totient is φ = 195306988800.

The previous prime is 195312521191. The next prime is 195312521309. The reversal of 195312521291 is 192125213591.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 192125213591 = 79 ⋅2431964729.

It is a cyclic number.

It is not a de Polignac number, because 195312521291 - 2³⁴ = 178132652107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195312521191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2712950 + ... + 2784011.

It is an arithmetic number, because the mean of its divisors is an integer number (48829513446).

Almost surely, 2^195312521291 is an apocalyptic number.

195312521291 is a deficient number, since it is larger than the sum of its proper divisors (5532493).

195312521291 is an equidigital number, since it uses as much as digits as its factorization.

195312521291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5532492.

The product of its digits is 48600, while the sum is 41.

The spelling of 195312521291 in words is "one hundred ninety-five billion, three hundred twelve million, five hundred twenty-one thousand, two hundred ninety-one".