191265644065 has 4 divisors (see below), whose sum is σ = 229518772884. Its totient is φ = 153012515248.

The previous prime is 191265644057. The next prime is 191265644099. The reversal of 191265644065 is 560446562191.

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

It can be written as a sum of positive squares in 2 ways, for example, as 115171318161 + 76094325904 = 339369^2 + 275852^2 .

It is a cyclic number.

It is not a de Polignac number, because 191265644065 - 2³ = 191265644057 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19126564402 + ... + 19126564411.

It is an arithmetic number, because the mean of its divisors is an integer number (57379693221).

Almost surely, 2^191265644065 is an apocalyptic number.

It is an amenable number.

191265644065 is a deficient number, since it is larger than the sum of its proper divisors (38253128819).

191265644065 is an equidigital number, since it uses as much as digits as its factorization.

191265644065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38253128818.

The product of its (nonzero) digits is 1555200, while the sum is 49.

The spelling of 191265644065 in words is "one hundred ninety-one billion, two hundred sixty-five million, six hundred forty-four thousand, sixty-five".