655550505509 has 2 divisors, whose sum is σ = 655550505510. Its totient is φ = 655550505508.

The previous prime is 655550505487. The next prime is 655550505517. The reversal of 655550505509 is 905505055556.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 634014062500 + 21536443009 = 796250^2 + 146753^2 .

It is a cyclic number.

It is not a de Polignac number, because 655550505509 - 2¹² = 655550501413 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (655550505569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327775252754 + 327775252755.

It is an arithmetic number, because the mean of its divisors is an integer number (327775252755).

Almost surely, 2^655550505509 is an apocalyptic number.

It is an amenable number.

655550505509 is a deficient number, since it is larger than the sum of its proper divisors (1).

655550505509 is an equidigital number, since it uses as much as digits as its factorization.

655550505509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4218750, while the sum is 50.

The spelling of 655550505509 in words is "six hundred fifty-five billion, five hundred fifty million, five hundred five thousand, five hundred nine".