655788109 has 2 divisors, whose sum is σ = 655788110. Its totient is φ = 655788108.

The previous prime is 655788103. The next prime is 655788139. The reversal of 655788109 is 901887556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 373648900 + 282139209 = 19330^2 + 16797^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-655788109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (655788103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327894054 + 327894055.

It is an arithmetic number, because the mean of its divisors is an integer number (327894055).

Almost surely, 2^655788109 is an apocalyptic number.

It is an amenable number.

655788109 is a deficient number, since it is larger than the sum of its proper divisors (1).

655788109 is an equidigital number, since it uses as much as digits as its factorization.

655788109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 604800, while the sum is 49.

The square root of 655788109 is about 25608.3601388297. The cubic root of 655788109 is about 868.8027345868.

The spelling of 655788109 in words is "six hundred fifty-five million, seven hundred eighty-eight thousand, one hundred nine".