195985409 has 4 divisors (see below), whose sum is σ = 196014420. Its totient is φ = 195956400.

The previous prime is 195985397. The next prime is 195985421. The reversal of 195985409 is 904589591.

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 is an interprime number because it is at equal distance from previous prime (195985397) and next prime (195985421).

It can be written as a sum of positive squares in 2 ways, for example, as 90307009 + 105678400 = 9503^2 + 10280^2 .

It is a cyclic number.

It is not a de Polignac number, because 195985409 - 2¹⁶ = 195919873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (195985429) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1559 + ... + 19859.

It is an arithmetic number, because the mean of its divisors is an integer number (49003605).

It is a Proth number, since it is equal to 5981 ⋅ 2¹⁵ + 1 and 5981 < 2¹⁵.

Almost surely, 2^195985409 is an apocalyptic number.

It is an amenable number.

195985409 is a deficient number, since it is larger than the sum of its proper divisors (29011).

195985409 is a wasteful number, since it uses less digits than its factorization.

195985409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29010.

The product of its (nonzero) digits is 583200, while the sum is 50.

The square root of 195985409 is about 13999.4788831585. The cubic root of 195985409 is about 580.8641587142.

The spelling of 195985409 in words is "one hundred ninety-five million, nine hundred eighty-five thousand, four hundred nine".