191379981697 has 8 divisors (see below), whose sum is σ = 194229009000. Its totient is φ = 188546481024.

The previous prime is 191379981673. The next prime is 191379981773. The reversal of 191379981697 is 796189973191.

It can be written as a sum of positive squares in 4 ways, for example, as 30607852401 + 160772129296 = 174951^2 + 400964^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 191379981697 - 2³⁵ = 157020243329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191379981607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3856822 + ... + 3906127.

It is an arithmetic number, because the mean of its divisors is an integer number (24278626125).

Almost surely, 2^191379981697 is an apocalyptic number.

It is an amenable number.

191379981697 is a deficient number, since it is larger than the sum of its proper divisors (2849027303).

191379981697 is an equidigital number, since it uses as much as digits as its factorization.

191379981697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7763315.

The product of its digits is 46294416, while the sum is 70.

The spelling of 191379981697 in words is "one hundred ninety-one billion, three hundred seventy-nine million, nine hundred eighty-one thousand, six hundred ninety-seven".