555991609 has 2 divisors, whose sum is σ = 555991610. Its totient is φ = 555991608.

The previous prime is 555991607. The next prime is 555991643. The reversal of 555991609 is 906199555.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 354493584 + 201498025 = 18828^2 + 14195^2 .

It is a cyclic number.

It is not a de Polignac number, because 555991609 - 2¹ = 555991607 is a prime.

Together with 555991607, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (555991607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 277995804 + 277995805.

It is an arithmetic number, because the mean of its divisors is an integer number (277995805).

Almost surely, 2^555991609 is an apocalyptic number.

It is an amenable number.

555991609 is a deficient number, since it is larger than the sum of its proper divisors (1).

555991609 is an equidigital number, since it uses as much as digits as its factorization.

555991609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 546750, while the sum is 49.

The square root of 555991609 is about 23579.4743155991. The cubic root of 555991609 is about 822.2857152501.

The spelling of 555991609 in words is "five hundred fifty-five million, nine hundred ninety-one thousand, six hundred nine".