197849708809 has 3 divisors (see below), whose sum is σ = 197850153613. Its totient is φ = 197849264006.

The previous prime is 197849708803. The next prime is 197849708867. The reversal of 197849708809 is 908807948791.

The square root of 197849708809 is 444803.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 908807948791 = 47629 ⋅19080979.

It is not a de Polignac number, because 197849708809 - 2²⁵ = 197816154377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (197849708803) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 222402 + ... + 667204.

Almost surely, 2^197849708809 is an apocalyptic number.

197849708809 is the 444803-rd square number.

197849708809 is the 222402-nd centered octagonal number.

It is an amenable number.

197849708809 is a deficient number, since it is larger than the sum of its proper divisors (444804).

197849708809 is an frugal number, since it uses more digits than its factorization.

197849708809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 889606 (or 444803 counting only the distinct ones).

The product of its (nonzero) digits is 73156608, while the sum is 70.

The spelling of 197849708809 in words is "one hundred ninety-seven billion, eight hundred forty-nine million, seven hundred eight thousand, eight hundred nine".