196778609 has 2 divisors, whose sum is σ = 196778610. Its totient is φ = 196778608.

The previous prime is 196778599. The next prime is 196778623. The reversal of 196778609 is 906877691.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 157753600 + 39025009 = 12560^2 + 6247^2 .

It is a cyclic number.

It is not a de Polignac number, because 196778609 - 2²⁰ = 195730033 is a prime.

It is not a weakly prime, because it can be changed into another prime (196778909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98389304 + 98389305.

It is an arithmetic number, because the mean of its divisors is an integer number (98389305).

Almost surely, 2^196778609 is an apocalyptic number.

It is an amenable number.

196778609 is a deficient number, since it is larger than the sum of its proper divisors (1).

196778609 is an equidigital number, since it uses as much as digits as its factorization.

196778609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The square root of 196778609 is about 14027.7799027501. The cubic root of 196778609 is about 581.6467361346.

The spelling of 196778609 in words is "one hundred ninety-six million, seven hundred seventy-eight thousand, six hundred nine".