556640509 has 2 divisors, whose sum is σ = 556640510. Its totient is φ = 556640508.

The previous prime is 556640507. The next prime is 556640527. The reversal of 556640509 is 905046655.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 547700409 + 8940100 = 23403^2 + 2990^2 .

It is a cyclic number.

It is not a de Polignac number, because 556640509 - 2¹ = 556640507 is a prime.

Together with 556640507, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (556640501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 278320254 + 278320255.

It is an arithmetic number, because the mean of its divisors is an integer number (278320255).

Almost surely, 2^556640509 is an apocalyptic number.

It is an amenable number.

556640509 is a deficient number, since it is larger than the sum of its proper divisors (1).

556640509 is an equidigital number, since it uses as much as digits as its factorization.

556640509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 162000, while the sum is 40.

The square root of 556640509 is about 23593.2301518889. The cubic root of 556640509 is about 822.6054885134.

The spelling of 556640509 in words is "five hundred fifty-six million, six hundred forty thousand, five hundred nine".