195816681 has 6 divisors (see below), whose sum is σ = 282846330. Its totient is φ = 130544448.

The previous prime is 195816653. The next prime is 195816707. The reversal of 195816681 is 186618591.

195816681 is a `hidden beast` number, since 1 + 9 + 581 + 6 + 68 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 110439081 + 85377600 = 10509^2 + 9240^2 .

It is not a de Polignac number, because 195816681 - 2⁹ = 195816169 is a prime.

It is a super-2 number, since 2×195816681² = 76688345115711522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (195815681) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10878696 + ... + 10878713.

It is an arithmetic number, because the mean of its divisors is an integer number (47141055).

Almost surely, 2^195816681 is an apocalyptic number.

It is an amenable number.

195816681 is a deficient number, since it is larger than the sum of its proper divisors (87029649).

195816681 is a wasteful number, since it uses less digits than its factorization.

195816681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21757415 (or 21757412 counting only the distinct ones).

The product of its digits is 103680, while the sum is 45.

The square root of 195816681 is about 13993.4513612618. The cubic root of 195816681 is about 580.6974180923.

It can be divided in two parts, 19581 and 6681, that added together give a palindrome (26262).

The spelling of 195816681 in words is "one hundred ninety-five million, eight hundred sixteen thousand, six hundred eighty-one".