195164517921 has 4 divisors (see below), whose sum is σ = 260219357232. Its totient is φ = 130109678612.

The previous prime is 195164517893. The next prime is 195164517923. The reversal of 195164517921 is 129715461591.

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: 129715461591 = 3 ⋅43238487197.

It is a cyclic number.

It is not a de Polignac number, because 195164517921 - 2¹⁴ = 195164501537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (195164517923) 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, 32527419651 + ... + 32527419656.

It is an arithmetic number, because the mean of its divisors is an integer number (65054839308).

Almost surely, 2^195164517921 is an apocalyptic number.

It is an amenable number.

195164517921 is a deficient number, since it is larger than the sum of its proper divisors (65054839311).

195164517921 is an equidigital number, since it uses as much as digits as its factorization.

195164517921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65054839310.

The product of its digits is 680400, while the sum is 51.

The spelling of 195164517921 in words is "one hundred ninety-five billion, one hundred sixty-four million, five hundred seventeen thousand, nine hundred twenty-one".