195690917947849 has 3 divisors (see below), whose sum is σ = 195690931936807. Its totient is φ = 195690903958892.

The previous prime is 195690917947831. The next prime is 195690917947907. The reversal of 195690917947849 is 948749719096591.

The square root of 195690917947849 is 13988957.

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.

It can be written as a sum of positive squares in only one way, i.e., 195196804551225 + 494113396624 = 13971285^2 + 702932^2 .

It is not a de Polignac number, because 195690917947849 - 2⁴⁵ = 160506545859017 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 195690917947849.

It is not an unprimeable number, because it can be changed into a prime (195690917947829) 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, 6994479 + ... + 20983435.

Almost surely, 2^{195690917947849} is an apocalyptic number.

195690917947849 is the 13988957-th square number.

195690917947849 is the 6994479-th centered octagonal number.

It is an amenable number.

195690917947849 is a deficient number, since it is larger than the sum of its proper divisors (13988958).

195690917947849 is an frugal number, since it uses more digits than its factorization.

195690917947849 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27977914 (or 13988957 counting only the distinct ones).

The product of its (nonzero) digits is 11110659840, while the sum is 88.

The spelling of 195690917947849 in words is "one hundred ninety-five trillion, six hundred ninety billion, nine hundred seventeen million, nine hundred forty-seven thousand, eight hundred forty-nine".