195918661129 has 9 divisors (see below), whose sum is σ = 202920731143. Its totient is φ = 189150451672.

The previous prime is 195918661073. The next prime is 195918661153. The reversal of 195918661129 is 921166819591.

The square root of 195918661129 is 442627.

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

It can be written as a sum of positive squares in only one way, i.e., 102734993529 + 93183667600 = 320523^2 + 305260^2 .

It is not a de Polignac number, because 195918661129 - 2⁹ = 195918660617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195918661229) 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, 12828552 + ... + 12843814.

Almost surely, 2^195918661129 is an apocalyptic number.

195918661129 is the 442627-th square number.

195918661129 is the 221314-th centered octagonal number.

It is an amenable number.

195918661129 is a deficient number, since it is larger than the sum of its proper divisors (7002070014).

195918661129 is an frugal number, since it uses more digits than its factorization.

195918661129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30584 (or 15292 counting only the distinct ones).

The product of its digits is 2099520, while the sum is 58.

The spelling of 195918661129 in words is "one hundred ninety-five billion, nine hundred eighteen million, six hundred sixty-one thousand, one hundred twenty-nine".