195945219649 has 9 divisors (see below), whose sum is σ = 196906477833. Its totient is φ = 194988637872.

The previous prime is 195945219641. The next prime is 195945219653. The reversal of 195945219649 is 946912549591.

The square root of 195945219649 is 442657.

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

It can be written as a sum of positive squares in 4 ways, for example, as 82354650625 + 113590569024 = 286975^2 + 337032^2 .

It is not a de Polignac number, because 195945219649 - 2³ = 195945219641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195945219641) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 101367487 + ... + 101369419.

It is an arithmetic number, because the mean of its divisors is an integer number (21878497537).

Almost surely, 2^195945219649 is an apocalyptic number.

195945219649 is the 442657-th square number.

195945219649 is the 221329-th centered octagonal number.

It is an amenable number.

195945219649 is a deficient number, since it is larger than the sum of its proper divisors (961258184).

195945219649 is an frugal number, since it uses more digits than its factorization.

195945219649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4324 (or 2162 counting only the distinct ones).

The product of its digits is 31492800, while the sum is 64.

Multiplying 195945219649 by its sum of digits (64), we get a square (12540494057536 = 3541256²).

The spelling of 195945219649 in words is "one hundred ninety-five billion, nine hundred forty-five million, two hundred nineteen thousand, six hundred forty-nine".