195581972813 has 4 divisors (see below), whose sum is σ = 197938382208. Its totient is φ = 193225563420.

The previous prime is 195581972681. The next prime is 195581972819. The reversal of 195581972813 is 318279185591.

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: 318279185591 = 4079 ⋅78028729.

It is a cyclic number.

It is not a de Polignac number, because 195581972813 - 2²⁶ = 195514863949 is a prime.

It is a super-2 number, since 2×195581972813² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (195581972819) 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, 1178204573 + ... + 1178204738.

It is an arithmetic number, because the mean of its divisors is an integer number (49484595552).

Almost surely, 2^195581972813 is an apocalyptic number.

It is an amenable number.

195581972813 is a deficient number, since it is larger than the sum of its proper divisors (2356409395).

195581972813 is an equidigital number, since it uses as much as digits as its factorization.

195581972813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2356409394.

The product of its digits is 5443200, while the sum is 59.

The spelling of 195581972813 in words is "one hundred ninety-five billion, five hundred eighty-one million, nine hundred seventy-two thousand, eight hundred thirteen".